PROSPERITY BANCSHARES INC - Annual Report: 2005 (Form 10-K)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

OR

Commission File Number 0-25051

PROSPERITY BANCSHARES, INC.^®

(Exact name of registrant as specified in its charter)

Registrant’s Telephone Number, Including Area Code: (713) 693-9300

Securities registered pursuant to Section 12(b) of the Act: None

Securities registered pursuant to Section 12(g) of the Act:

Common Stock, par value

$1.00 per share

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 (d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of the Form 10-K or any amendment of this Form 10-K.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check One):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    Yes  ¨    No  x

The aggregate market value of the shares of Common Stock held by non-affiliates, based on the closing price of the Common Stock on the Nasdaq National Market System on June 30, 2005 was approximately $620.2 million.

As of March 1, 2006, the number of outstanding shares of Common Stock was 27,864,894.

Documents Incorporated by Reference:

Portions of the Company’s Proxy Statement relating to the 2006 Annual Meeting of Shareholders, which will be filed within 120 days after December 31, 2005, are incorporated by reference into Part III, Items 10-14 of this Form 10-K.

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PROSPERITY BANCSHARES, INC.^®

2005 ANNUAL REPORT ON FORM 10-K

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PART I

ITEM 1. BUSINESS

General

Prosperity Bancshares, Inc.^®, a Texas corporation (the “Company”), was formed in 1983 as a vehicle to acquire the former Allied Bank in Edna, Texas which was chartered in 1949 as The First National Bank of Edna. The Company is a registered financial holding company that derives substantially all of its revenues and income from the operation of its bank subsidiary, Prosperity Bank^® (“Prosperity Bank^®” or the “Bank”). The Bank provides a broad line of financial products and services to small and medium-sized businesses and consumers. As of December 31, 2005, the Bank operated eight-five (85) full-service banking locations, with thirty-three (33) in the Greater Houston Consolidated Metropolitan Statistical Area (“CMSA”), seventeen (17) in fifteen contiguous counties situated south and southwest of Houston and extending into South Texas, six (6) in the Austin, Texas area, sixteen (16) in the Corpus Christi, Texas area, two (2) in the east Texas area and eleven (11) in the Dallas, Texas area. The Greater Houston CMSA consists of Austin, Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, San Jacinto and Waller counties. The Company’s headquarters are located at Prosperity Bank Plaza, 4295 San Felipe in Houston, Texas and its telephone number is (713) 693-9300. The Company’s website address is www.prosperitybanktx.com.

The Company’s market consists of the communities served by its banking centers. US Highway 59 (scheduled to become Interstate Highway 69), which serves as the primary “NAFTA Highway” linking the interior United States and Mexico, runs directly through the center of the Company’s market area. The increased traffic along this NAFTA Highway has enhanced economic activity in the Company’s market area and created opportunities for growth. The diverse nature of the economies in each local market served by the Company provides the Company with a varied customer base and allows the Company to spread its lending risk throughout a number of different industries including farming, ranching, petrochemicals, manufacturing, tourism, recreation and professional service firms and their principals. The Company’s market areas outside of Houston, Dallas, Corpus Christi and Austin are dominated by either small community banks or branches of large regional banks. Management believes that the Company, as one of the few mid-sized financial institutions that combines responsive community banking with the sophistication of a regional bank holding company, has a competitive advantage in its market areas and excellent growth opportunities through acquisitions, new banking center locations and additional business development.

Operating under a community banking philosophy, the Company seeks to develop broad customer relationships based on service and convenience while maintaining its conservative approach to lending and strong asset quality. The Company has grown through a combination of internal growth, the acquisition of community banks, branches of banks and the opening of new banking centers. Utilizing a low cost of funds and employing stringent cost controls, the Company has been profitable in every full year of its existence, including the period of adverse economic conditions in Texas in the late 1980s. From 1988 to 1992, as a sound and profitable institution, the Company took advantage of this economic downturn and acquired the deposits and certain assets of failed banks in West Columbia, El Campo and Cuero, Texas and two failed banks in Houston, which diversified the Company’s franchise and increased its core deposits. The Company opened a full-service banking center in Victoria, Texas in 1993 and the following year established a banking center in Bay City, Texas. The Company expanded its Bay City presence in 1996 with the acquisition of an additional branch location from Norwest Bank Texas (now Wells Fargo), and in 1997, the Company acquired the Angleton, Texas branch of Wells Fargo Bank. In 1998, the Company enhanced its West Columbia Banking Center with the purchase of a commercial bank branch located in West Columbia and acquired Union State Bank in East Bernard, Texas.

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From December 31, 1998 through December 31, 2005, the Company grew through internal growth and the completion of the following acquisitions:

2005 Acquisitions

On December 1, 2005, the Company completed its acquisition of Grapeland Bancshares, Inc. (the “Grapeland acquisition”), Grapeland, Texas. Under the terms of the agreement, Grapeland merged into the Company and subsequently, Grapeland’s wholly owned subsidiary, First State Bank of Grapeland, merged into the Bank. The Company issued 232,888 shares of its common stock for all of the issued and outstanding capital stock of Grapeland. Grapeland was privately held and operated two (2) banking offices in Grapeland and Crockett, Texas, both of which became full service banking centers of the Company.

On March 1, 2005, the Company completed its acquisition of First Capital Bankers, Inc. (the “First Capital acquisition”), Corpus Christi, Texas. Under the terms of the agreement, First Capital was merged into the Company and subsequently, First Capital’s wholly owned subsidiary, FirstCapital Bank, s.s.b., was merged into the Bank. The Company issued approximately 5.079 million shares of its common stock for all of the issued and outstanding capital stock of First Capital and converted all outstanding options to acquire First Capital common stock into options to acquire approximately 234,000 shares of Company common stock. First Capital was privately held and operated thirty-two (32) banking offices in and around Corpus Christi, Houston and Victoria, Texas, five of which were closed and consolidated with existing banking centers of the Company.

Pending Acquisition

On November 16, 2005, the Company announced its proposed acquisition of SNB Bancshares, Inc. (“SNB”), Sugar Land, Texas. Under the terms of the agreement, SNB will merge into the Company and subsequently, SNB’s wholly owned subsidiary, Southern National Bank of Texas will merge into the Bank. The Company expects to issue approximately 4.448 million shares of its common stock and approximately $93.0 million in cash for all of the issued and outstanding capital stock of SNB subject to adjustment as provided in the

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agreement. SNB is publicly traded and operates five (5) banking offices in Fort Bend County, Houston and Katy, Texas and two (2) stand alone motor banks in Houston, Texas. SNB has an additional banking office under construction in Katy, Texas. As of December 31, 2005, SNB had, on a consolidated basis, total assets of $1.025 billion, loans (including loans held for sale) of $652.8 million, deposits of $892.0 million and shareholders’ equity of $82.5 million.

Recent Developments

On February 28, 2006, the Company redeemed in full the $6.2 million in junior subordinated debentures issued to Paradigm Capital Trust II. Paradigm Capital Trust II in turn redeemed in full the trust preferred securities and common securities it issued.

Available Information

The Company’s website address is www.prosperitybanktx.com. The Company makes available free of charge on or through its website its annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and all amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, as soon as reasonably practicable after such material is electronically filed with or furnished to the Securities and Exchange Commission. Information contained on the Company’s website is not incorporated by reference into this annual report on Form 10-K and is not part of this or any other report.

Officers and Associates

The Company’s directors and officers are important to the Company’s success and play a key role in the Company’s business development efforts by actively participating in civic and public service activities in the communities served by the Company, including the Rotary Club, Lion’s Club, Pilot Club, United Way and Chamber of Commerce.

The Company has invested heavily in its officers and associates by recruiting talented officers in its market areas and providing them with economic incentive in the form of stock options and bonuses based on cross-selling performance. The senior management team has substantial experience in the Houston, Dallas, Austin and Corpus Christi markets and the surrounding communities in which the Company has a presence. Each banking center location is administered by a local president or manager with knowledge of the community and lending expertise in the specific industries found in the community. The Company entrusts its banking center Presidents and Managers with authority and flexibility within general parameters with respect to product pricing and decision making in order to avoid the bureaucratic structure of larger banks. The Company operates each banking center as a separate profit center, maintaining separate data with respect to each banking center’s net interest income, efficiency ratio, deposit growth, loan growth and overall profitability. Banking center presidents and managers are accountable for performance in these areas and compensated accordingly. The Company’s local banking centers have no 1-800 telephone numbers. Each banking center has its own listed local business telephone number, which enables a customer to be served by a local banker with decision making authority.

As of December 31, 2005, the Company and the Bank had 859 full-time equivalent associates, 299 of whom were officers of the Bank. The Company provides medical and hospitalization insurance to its full-time associates. The Company considers its relations with associates to be excellent. Neither the Company nor the Bank is a party to any collective bargaining agreement.

Banking Activities

The Company, through the Bank, offers a variety of traditional loan and deposit products to its customers, which consist primarily of consumers and small and medium-sized businesses. The Bank tailors its products to the specific needs of customers in a given market. At December 31, 2005, the Bank maintained approximately

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185,000 separate deposit accounts and 21,000 separate loan accounts and 23.1% of the Bank’s total deposits were noninterest-bearing demand deposits. For the year ended December 31, 2005, the Company’s average cost of funds was 1.75% and the Company’s average cost of deposits (excluding all borrowings) was 1.56%.

The Company has been an active mortgage lender, with commercial mortgage and 1-4 family residential loans comprising 57.0% of the Company’s total loans as of December 31, 2005. The Company also offers loans for automobiles and other consumer durables, home equity loans, debit cards, internet banking and other cash management services and automated telephone banking. By offering certificates of deposit, checking with interest accounts, savings accounts and overdraft protection at competitive rates, the Company gives its depositors a full range of traditional deposit products.

The businesses targeted by the Company in its lending efforts are primarily those that require loans in the $100,000 to $8.0 million range. The Company offers these businesses a broad array of loan products including term loans, lines of credit and loans for working capital, business expansion and the purchase of equipment and machinery, interim construction loans for builders and owner-occupied commercial real estate loans. For its business customers, the Company has developed a specialized checking product called Small Business Checking which provides fixed discounted fees for checking.

Business Strategies

The Company’s main objective is to increase deposits and loans internally, as well as through additional expansion opportunities, while maintaining efficiency, individualized customer service and maximizing profitability. To achieve this objective, the Company has employed the following strategic goals:

Continue Community Banking Emphasis. The Company intends to continue operating as a community banking organization focused on meeting the specific needs of consumers and small and medium-sized businesses in its market areas. The Company will continue to provide a high degree of responsiveness combined with a wide variety of banking products and services. The Company staffs its banking centers with experienced bankers with lending expertise in the specific industries found in the community, giving them authority to make certain pricing and credit decisions, thereby attempting to avoid the bureaucratic structure of larger banks.

Increase Loan Volume and Diversify Loan Portfolio. While maintaining its conservative approach to lending, the Company has emphasized both new and existing loan products, focusing on growing its construction, commercial mortgage and commercial loan portfolios. During the two-year period from December 31, 2003 to December 31, 2005, the Company’s construction loans grew from $36.5 million to $206.7 million, or 466.6%. The Company’s commercial and industrial loans grew from $94.0 million to $222.8 million, or 137.0%, and its commercial mortgages increased from $260.9 million to $566.4 million, or 117.1% for the same period. In addition, the Company targets professional service firms including legal and medical practices for both loans secured by owner-occupied premises and personal loans to their principals.

Continue Strict Focus on Efficiency. The Company plans to maintain its stringent cost control practices and policies. The Company has invested significantly in the infrastructure required to centralize many of its critical operations, such as data processing and loan processing. For its banking centers, which the Company operates as independent profit centers, the Company supplies complete support in the areas of loan review, internal audit, compliance and training. Management believes that this centralized infrastructure can accommodate substantial additional growth while enabling the Company to minimize operational costs through certain economies of scale.

Enhance Cross-Selling. The Company recognizes that its customer base provides significant opportunities to cross-sell various products and it seeks to develop broader customer relationships by identifying cross-selling opportunities. The Company uses incentives and friendly competition to encourage cross-selling efforts and increase cross-selling results among its associates. Officers and associates have access to each customer’s existing and related account relationships and are better able to inform customers of additional products when customers visit or call the various banking centers or use their drive-in facilities. In addition, the Company includes product information in monthly statements and other mailings.

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Maintain Strong Asset Quality. The Company intends to maintain the strong asset quality that has been representative of its historical loan portfolio. As the Company diversifies and increases its lending activities, it may face higher risks of nonpayment and increased risks in the event of economic downturns. The Company intends, however, to continue to employ the strict underwriting guidelines and comprehensive loan review process that has contributed to its low incidence of nonperforming assets and its minimal charge-offs in relation to its size.

Expand Market Share Through Internal Growth and a Disciplined Acquisition Strategy. The Company intends to continue seeking opportunities, both inside and outside its existing markets, to expand either by acquiring existing banks or branches of banks or by establishing new banking centers. All of the Company’s acquisitions have been accretive to earnings within 12 months after acquisition date and generally have supplied the Company with relatively low-cost deposits which have been used to fund the Company’s lending and investing activities. However, the Company makes no guarantee that future acquisitions, if any, will be accretive to earnings within any particular time period. Factors used by the Company to evaluate expansion opportunities include the similarity in management and operating philosophies, whether the acquisition will be accretive to earnings and enhance shareholder value, the ability to achieve economies of scale to improve the efficiency ratio and the opportunity to enhance the Company’s market presence.

Competition

The banking business is highly competitive, and the profitability of the Company depends principally on its ability to compete in its market areas. The Company competes with other commercial banks, savings banks, savings and loan associations, credit unions, finance companies, mutual funds, insurance companies, brokerage and investment banking firms, asset-based nonbank lenders and certain other nonfinancial entities, including retail stores which may maintain their own credit programs and certain governmental organizations which may offer more favorable financing than the Company. The Company believes it has been able to compete effectively with other financial institutions by emphasizing customer service, technology and responsive decision-making with respect to loans; by establishing long-term customer relationships and building customer loyalty; and by providing products and services designed to address the specific needs of its customers.

Supervision and Regulation

The supervision and regulation of bank holding companies and their subsidiaries is intended primarily for the protection of depositors, the deposit insurance funds of the Federal Deposit Insurance Corporation (“FDIC”) and the banking system as a whole, and not for the protection of the bank holding company shareholders or creditors. The banking agencies have broad enforcement power over bank holding companies and banks including the power to impose substantial fines and other penalties for violations of laws and regulations.

The following description summarizes some of the laws to which the Company and the Bank are subject. References in this annual report on Form 10-K to applicable statutes and regulations are brief summaries thereof, do not purport to be complete, and are qualified in their entirety by reference to such statutes and regulations.

The Company

The Company is a financial holding company pursuant to the Gramm-Leach-Bliley Act and a bank holding company registered under the Bank Holding Company Act of 1956, as amended (“BHCA”). Accordingly, the Company is subject to supervision, regulation and examination by the Board of Governors of the Federal Reserve System (“Federal Reserve Board”). The Gramm-Leach-Bliley Act, the BHCA and other federal laws subject financial and bank holding companies to particular restrictions on the types of activities in which they may engage, and to a range of supervisory requirements and activities, including regulatory enforcement actions for violations of laws and regulations.

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Regulatory Restrictions on Dividends; Source of Strength. It is the policy of the Federal Reserve Board that bank holding companies should pay cash dividends on common stock only out of income available over the past year and only if prospective earnings retention is consistent with the organization’s expected future needs and financial condition. The policy provides that bank holding companies should not maintain a level of cash dividends that undermines the bank holding company’s ability to serve as a source of strength to its banking subsidiaries.

Under Federal Reserve Board policy, a bank holding company is expected to act as a source of financial strength to each of its banking subsidiaries and commit resources to their support. Such support may be required at times when, absent this Federal Reserve Board policy, a holding company may not be inclined to provide it. As discussed below, a bank holding company, in certain circumstances, could be required to guarantee the capital plan of an undercapitalized banking subsidiary.

In the event of a bank holding company’s bankruptcy under Chapter 11 of the U.S. Bankruptcy Code, the trustee will be deemed to have assumed and is required to cure immediately any deficit under any commitment by the debtor holding company to any of the federal banking agencies to maintain the capital of an insured depository institution. Any claim for breach of such obligation will generally have priority over most other unsecured claims.

Scope of Permissible Activities. Under the BHCA, bank holding companies generally may not acquire a direct or indirect interest in or control of more than 5% of the voting shares of any company that is not a bank or bank holding company or from engaging in activities other than those of banking, managing or controlling banks or furnishing services to or performing services for its subsidiaries, except that it may engage in, directly or indirectly, certain activities that the Federal Reserve Board determined to be closely related to banking or managing and controlling banks as to be a proper incident thereto. In approving acquisitions or the addition of activities, the Federal Reserve considers whether the acquisition or the additional activities can reasonably be expected to produce benefits to the public, such as greater convenience, increased competition, or gains in efficiency, that outweigh such possible adverse effects as undue concentration of resources decreased or unfair competition, conflicts of interest or unsound banking practices.

Notwithstanding the foregoing, the Gramm-Leach-Bliley Act, effective March 11, 2000, eliminated the barriers to affiliations among banks, securities firms, insurance companies and other financial service providers and permits bank holding companies to become financial holding companies and thereby affiliate with securities firms and insurance companies and engage in other activities that are financial in nature. The Gramm-Leach-Bliley Act defines “financial in nature” to include securities underwriting, dealing and market making; sponsoring mutual funds and investment companies; insurance underwriting and agency; merchant banking activities; and activities that the Federal Reserve Board has determined to be closely related to banking. No regulatory approval will be required for a financial holding company to acquire a company, other than a bank or savings association, engaged in activities that are financial in nature or incidental to activities that are financial in nature, as determined by the Federal Reserve Board.

Under the Gramm-Leach-Bliley Act, a bank holding company may become a financial holding company by filing a declaration with the Federal Reserve Board if each of its subsidiary banks is well capitalized under the Federal Deposit Insurance Corporation Improvement Act (“FDICIA”) prompt corrective action provisions, is well managed, and has at least a satisfactory rating under the Community Reinvestment Act of 1977 (“CRA”). The Company became a financial holding company on April 18, 2000.

While the Federal Reserve Board is the “umbrella” regulator for financial holding companies and has the power to examine banking organizations engaged in new activities, regulation and supervision of activities which are financial in nature or determined to be incidental to such financial activities will be handled along functional lines. Accordingly, activities of subsidiaries of a financial holding company will be regulated by the agency or authorities with the most experience regulating that activity as it is conducted in a financial holding company.

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Safe and Sound Banking Practices. Bank holding companies are not permitted to engage in unsafe and unsound banking practices. The Federal Reserve Board’s Regulation Y, for example, generally requires a holding company to give the Federal Reserve Board prior notice of any redemption or repurchase of its own equity securities, if the consideration to be paid, together with the consideration paid for any repurchases or redemptions in the preceding year, is equal to 10% or more of the company’s consolidated net worth. The Federal Reserve Board may oppose the transaction if it believes that the transaction would constitute an unsafe or unsound practice or would violate any law or regulation. Depending upon the circumstances, the Federal Reserve Board could take the position that paying a dividend would constitute an unsafe or unsound banking practice.

The Federal Reserve Board has broad authority to prohibit activities of bank holding companies and their nonbanking subsidiaries which represent unsafe and unsound banking practices or which constitute violations of laws or regulations, and can assess civil money penalties for certain activities conducted on a knowing and reckless basis, if those activities caused a substantial loss to a depository institution. The penalties can be as high as $1.0 million for each day the activity continues.

Anti-Tying Restrictions. Bank holding companies and their affiliates are prohibited from tying the provision of certain services, such as extensions of credit, to other services offered by a holding company or its affiliates.

Capital Adequacy Requirements. The Federal Reserve Board has adopted a system using risk-based capital guidelines to evaluate the capital adequacy of bank holding companies. Under the guidelines, specific categories of assets are assigned different risk weights, based generally on the perceived credit risk of the asset. These risk weights are multiplied by corresponding asset balances to determine a “risk-weighted” asset base. The guidelines require a minimum ratio of total capital to total tangible risk-weighted assets of 8.0% (of which at least 4.0% is required to consist of Tier 1 capital elements). Total capital is the sum of Tier 1 and Tier 2 capital. As of December 31, 2005, the Company’s ratio of Tier 1 capital to total tangible risk-weighted assets was 15.34% and its ratio of total capital to total tangible risk-weighted assets was 16.37%. Tangible risk-weighted assets are calculated as total risk-weighted assets less intangible assets such as goodwill and core deposit intangibles.

In addition to the risk-based capital guidelines, the Federal Reserve Board uses a leverage ratio as an additional tool to evaluate the capital adequacy of bank holding companies. The leverage ratio is a company’s Tier 1 capital divided by its average total tangible consolidated assets. Certain highly rated bank holding companies may maintain a minimum leverage ratio of 3.0%, but other bank holding companies are required to maintain a leverage ratio of 4.0%. As of December 31, 2005, the Company’s leverage ratio was 7.83%.

The federal banking agencies’ risk-based and leverage ratios are minimum supervisory ratios generally applicable to banking organizations that meet certain specified criteria, assuming that they have the highest regulatory rating. Banking organizations not meeting these criteria are expected to operate with capital positions well above the minimum ratios. The federal bank regulatory agencies may set capital requirements for a particular banking organization that are higher than the minimum ratios when circumstances warrant. Federal Reserve Board guidelines also provide that banking organizations experiencing internal growth or making acquisitions will be expected to maintain strong capital positions substantially above the minimum supervisory levels, without significant reliance on intangible assets.

Imposition of Liability for Undercapitalized Subsidiaries. Bank regulators are required to take “prompt corrective action” to resolve problems associated with insured depository institutions whose capital declines below certain levels. In the event an institution becomes “undercapitalized,” it must submit a capital restoration plan. The capital restoration plan will not be accepted by the regulators unless each company having control of the undercapitalized institution guarantees the subsidiary’s compliance with the capital restoration plan up to a certain specified amount. Any such guarantee from a depository institution’s holding company is entitled to a priority of payment in bankruptcy.

The aggregate liability of the holding company of an undercapitalized bank is limited to the lesser of 5% of the institution’s assets at the time it became undercapitalized or the amount necessary to cause the institution to

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be “adequately capitalized.” The bank regulators have greater power in situations where an institution becomes “significantly” or “critically” undercapitalized or fails to submit a capital restoration plan. For example, a bank holding company controlling such an institution can be required to obtain prior Federal Reserve Board approval of proposed dividends, or might be required to consent to a consolidation or to divest the troubled institution or other affiliates.

Acquisitions by Bank Holding Companies. The BHCA requires every bank holding company to obtain the prior approval of the Federal Reserve Board before it may acquire all or substantially all of the assets of any bank, or ownership or control of any voting shares of any bank, if after such acquisition it would own or control, directly or indirectly, more than 5% of the voting shares of such bank. In approving bank acquisitions by bank holding companies, the Federal Reserve Board is required to consider the financial and managerial resources and future prospects of the bank holding company and the banks concerned, the convenience and needs of the communities to be served, and various competitive factors.

Control Acquisitions. The Change in Bank Control Act prohibits a person or group of persons from acquiring “control” of a bank holding company unless the Federal Reserve Board has been notified and has not objected to the transaction. Under a rebuttable presumption established by the Federal Reserve Board, the acquisition of 10% or more of a class of voting stock of a bank holding company with a class of securities registered under Section 12 of the Exchange Act, such as the Company, would, under the circumstances set forth in the presumption, constitute acquisition of control of the Company.

In addition, any entity is required to obtain the approval of the Federal Reserve Board under the BHCA before acquiring 25% (5% in the case of an acquirer that is a bank holding company) or more of the outstanding Common Stock of the Company, or otherwise obtaining control or a “controlling influence” over the Company.

The Bank

The Bank is a Texas-chartered banking association, the deposits of which are insured by the Bank Insurance Fund (“BIF”) of the FDIC. The Bank is not a member of the Federal Reserve System; therefore, the Bank is subject to supervision and regulation by the FDIC and the Texas Banking Department. Such supervision and regulation subject the Bank to special restrictions, requirements, potential enforcement actions and periodic examination by the FDIC and the Texas Banking Department. Because the Federal Reserve Board regulates the bank holding company parent of the Bank, the Federal Reserve Board also has supervisory authority which directly affects the Bank.

Equivalence to National Bank Powers. The Texas Constitution, as amended in 1986, provides that a Texas-chartered bank has the same rights and privileges that are or may be granted to national banks domiciled in Texas. To the extent that the Texas laws and regulations may have allowed state-chartered banks to engage in a broader range of activities than national banks, the Federal Deposit Insurance Corporation Improvement Act of 1991 (“FDICIA”) has operated to limit this authority. FDICIA provides that no state bank or subsidiary thereof may engage as principal in any activity not permitted for national banks, unless the institution complies with applicable capital requirements and the FDIC determines that the activity poses no significant risk to the insurance fund. In general, statutory restrictions on the activities of banks are aimed at protecting the safety and soundness of depository institutions.

Financial Modernization. Under the Gramm-Leach-Bliley Act, a national bank may establish a financial subsidiary and engage, subject to limitations on investment, in activities that are financial in nature, other than insurance underwriting as principal, insurance company portfolio investment, real estate development, real estate investment and annuity issuance. To do so, a bank must be well capitalized, well managed and have a CRA rating of satisfactory or better. Subsidiary banks of a financial holding company or national banks with financial subsidiaries must remain well capitalized and well managed in order to continue to engage in activities that are financial in nature without regulatory actions or restrictions, which could include divestiture of the financial in

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nature subsidiary or subsidiaries. In addition, a financial holding company or a bank may not acquire a company that is engaged in activities that are financial in nature unless each of the subsidiary banks of the financial holding company or the bank has a CRA rating of satisfactory of better.

Although the powers of state chartered banks are not specifically addressed in the Gramm-Leach-Bliley Act, Texas-chartered banks such as the Bank, will have the same if not greater powers as national banks through the parity provision contained in the Texas Constitution.

Branching. Texas law provides that a Texas-chartered bank can establish a branch anywhere in Texas provided that the branch is approved in advance by the Texas Banking Department. The branch must also be approved by the FDIC, which considers a number of factors, including financial history, capital adequacy, earnings prospects, character of management, needs of the community and consistency with corporate powers.

Restrictions on Transactions with Affiliates and Insiders. Transactions between the Bank and its nonbanking affiliates, including the Company, are subject to Section 23A of the Federal Reserve Act. In general, Section 23A imposes limits on the amount of such transactions, and also requires certain levels of collateral for loans to affiliated parties. It also limits the amount of advances to third parties which are collateralized by the securities or obligations of the Company or its subsidiaries.

Affiliate transactions are also subject to Section 23B of the Federal Reserve Act which generally requires that certain transactions between the Bank and its affiliates be on terms substantially the same, or at least as favorable to the Bank, as those prevailing at the time for comparable transactions with or involving other nonaffiliated persons. The Federal Reserve has also issued Regulation W which codifies prior regulations under Sections 23A and 23B of the Federal Reserve Act and interpretive guidance with respect to affiliate transactions.

The restrictions on loans to directors, executive officers, principal shareholders and their related interests (collectively referred to herein as “insiders”) contained in the Federal Reserve Act and Regulation O apply to all insured institutions and their subsidiaries and holding companies. These restrictions include limits on loans to one borrower and conditions that must be met before such a loan can be made. There is also an aggregate limitation on all loans to insiders and their related interests. These loans cannot exceed the institution’s total unimpaired capital and surplus, and the FDIC may determine that a lesser amount is appropriate. Insiders are subject to enforcement actions for knowingly accepting loans in violation of applicable restrictions.

Restrictions on Distribution of Subsidiary Bank Dividends and Assets. Dividends paid by the Bank have provided a substantial part of the Company’s operating funds and for the foreseeable future it is anticipated that dividends paid by the Bank to the Company will continue to be the Company’s principal source of operating funds. Capital adequacy requirements serve to limit the amount of dividends that may be paid by the Bank. Under federal law, the Bank cannot pay a dividend if, after paying the dividend, the Bank will be “undercapitalized.” The FDIC may declare a dividend payment to be unsafe and unsound even though the Bank would continue to meet its capital requirements after the dividend. Because the Company is a legal entity separate and distinct from its subsidiaries, its right to participate in the distribution of assets of any subsidiary upon the subsidiary’s liquidation or reorganization will be subject to the prior claims of the subsidiary’s creditors. In the event of a liquidation or other resolution of an insured depository institution, the claims of depositors and other general or subordinated creditors are entitled to a priority of payment over the claims of holders of any obligation of the institution to its shareholders, including any depository institution holding company (such as the Company) or any shareholder or creditor thereof.

Examinations. The FDIC periodically examines and evaluates insured banks. Based on such an evaluation, the FDIC may revalue the assets of the institution and require that it establish specific reserves to compensate for the difference between the FDIC-determined value and the book value of such assets. The Texas Banking Department also conducts examinations of state banks but may accept the results of a federal examination in lieu of conducting an independent examination. In addition, the FDIC and Texas Banking Department may elect to conduct a joint examination.

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Audit Reports. Insured institutions with total assets of $500 million or more must submit annual audit reports prepared by independent auditors to federal and state regulators. In some instances, the audit report of the institution’s holding company can be used to satisfy this requirement. Auditors must receive examination reports, supervisory agreements and reports of enforcement actions. In addition, financial statements prepared in accordance with generally accepted accounting principles, management’s certifications concerning responsibility for the financial statements, internal controls and compliance with legal requirements designated by the FDIC, and an attestation by the auditor regarding the statements of management relating to the internal controls must be submitted. For institutions with total assets of more than $3 billion, independent auditors may be required to review quarterly financial statements. FDICIA requires that independent audit committees be formed, consisting of outside directors only. The committees of such institutions must include members with experience in banking or financial management, must have access to outside counsel, and must not include representatives of large customers.

Capital Adequacy Requirements. The FDIC has adopted regulations establishing minimum requirements for the capital adequacy of insured institutions. The FDIC may establish higher minimum requirements if, for example, a bank has previously received special attention or has a high susceptibility to interest rate risk.

The FDIC’s risk-based capital guidelines generally require state banks to have a minimum ratio of Tier 1 capital to total tangible risk-weighted assets of 4.0% and a ratio of total capital to total tangible risk-weighted assets of 8.0%. The capital categories have the same definitions for the Bank as for the Company. As of December 31, 2005, the Bank’s ratio of Tier 1 capital to total tangible risk-weighted assets was 15.04% and its ratio of total capital to total tangible risk-weighted assets was 16.08%.

The FDIC’s leverage guidelines require state banks to maintain Tier 1 capital of no less than 4.0% of average total tangible assets, except in the case of certain highly rated banks for which the requirement is 3.0% of average total assets. The Texas Banking Department has issued a policy which generally requires state chartered banks to maintain a leverage ratio (defined in accordance with federal capital guidelines) of 5.0%. As of December 31, 2005, the Bank’s ratio of Tier 1 capital to average total assets (leverage ratio) was 7.67%.

Corrective Measures for Capital Deficiencies. The federal banking regulators are required to take “prompt corrective action” with respect to capital-deficient institutions. Agency regulations define, for each capital category, the levels at which institutions are “well-capitalized,” “adequately capitalized,” “under capitalized,” “significantly under capitalized” and “critically under capitalized.” A “well-capitalized” bank has a total risk-based capital ratio of 10.0% or higher; a Tier 1 risk-based capital ratio of 6.0% or higher; a leverage ratio of 5.0% or higher; and is not subject to any written agreement, order or directive requiring it to maintain a specific capital level for any capital measure. An “adequately capitalized” bank has a total risk-based capital ratio of 8.0% or higher; a Tier 1 risk-based capital ratio of 4.0% or higher; a leverage ratio of 4.0% or higher (3.0% or higher if the bank was rated a composite 1 in its most recent examination report and is not experiencing significant growth); and does not meet the criteria for a well capitalized bank. A bank is “under capitalized” if it fails to meet any one of the ratios required to be adequately capitalized. The Bank is classified as “well-capitalized” for purposes of the FDIC’s prompt corrective action regulations.

In addition to requiring undercapitalized institutions to submit a capital restoration plan, agency regulations contain broad restrictions on certain activities of undercapitalized institutions including asset growth, acquisitions, branch establishment and expansion into new lines of business. With certain exceptions, an insured depository institution is prohibited from making capital distributions, including dividends, and is prohibited from paying management fees to control persons if the institution would be undercapitalized after any such distribution or payment.

As an institution’s capital decreases, the FDIC’s enforcement powers become more severe. A significantly undercapitalized institution is subject to mandated capital raising activities, restrictions on interest rates paid and transactions with affiliates, removal of management and other restrictions. The FDIC has only very limited discretion in dealing with a critically undercapitalized institution and is virtually required to appoint a receiver or conservator.

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Banks with risk-based capital and leverage ratios below the required minimums may also be subject to certain administrative actions, including the termination of deposit insurance upon notice and hearing, or a temporary suspension of insurance without a hearing in the event the institution has no tangible capital.

Deposit Insurance Assessments. The Bank must pay assessments to the FDIC for federal deposit insurance protection. The FDIC has adopted a risk-based assessment system as required by FDICIA. Under this system, FDIC-insured depository institutions pay insurance premiums at rates based on their risk classification. Institutions assigned to higher risk classifications (that is, institutions that pose a greater risk of loss to their respective deposit insurance funds) pay assessments at higher rates than institutions that pose a lower risk. An institution’s risk classification is assigned based on its capital levels and the level of supervisory concern the institution poses to the regulators. In addition, the FDIC can impose special assessments in certain instances. The current range of BIF assessments is between 0% and 0.27% of deposits.

The FDIC established a process for raising or lowering all rates for insured institutions semi-annually if conditions warrant a change. Under this system, the FDIC has the flexibility to adjust the assessment rate schedule twice a year without seeking prior public comment, but only within a range of five cents per $100 above or below the premium schedule adopted. Changes in the rate schedule outside the five cent range above or below the current schedule can be made by the FDIC only after a full rulemaking with opportunity for public comment.

In addition to BIF assessments, banks insured under the BIF are required to pay a portion of the interest due on bonds that were issued by the Financing Corporation (“FICO”) to help shore up the ailing Federal Savings and Loan Insurance Corporation in 1987. With regard to the assessment for the FICO obligation, for the fourth quarter 2005, the BIF rate was .00134% of deposits.

Brokered Deposit Restrictions. Adequately capitalized institutions cannot accept, renew or roll over brokered deposits except with a waiver from the FDIC, and are subject to restrictions on the interest rates that can be paid on such deposits. Undercapitalized institutions may not accept, renew, or roll over brokered deposits.

Cross-Guarantee Provisions. The Financial Institutions Reform, Recovery and Enforcement Act of 1989 (“FIRREA”) contains a “cross-guarantee” provision which generally makes commonly controlled insured depository institutions liable to the FDIC for any losses incurred in connection with the failure of a commonly controlled depository institution.

Community Reinvestment Act. The Community Reinvestment Act (“CRA”) and the regulations issued thereunder are intended to encourage banks to help meet the credit needs of their service area, including low and moderate income neighborhoods, consistent with the safe and sound operations of the banks. These regulations also provide for regulatory assessment of a bank’s record in meeting the needs of its service area when considering applications to establish branches, merger applications and applications to acquire the assets and assume the liabilities of another bank. FIRREA requires federal banking agencies to make public a rating of a bank’s performance under the CRA. In the case of a bank holding company, the CRA performance record of the banks involved in the transaction are reviewed in connection with the filing of an application to acquire ownership or control of shares or assets of a bank or to merge with any other bank holding company. An unsatisfactory record can substantially delay or block the transaction.

Consumer Laws and Regulations. In addition to the laws and regulations discussed herein, the Bank is also subject to certain consumer laws and regulations that are designed to protect consumers in transactions with banks. While the list set forth herein is not exhaustive, these laws and regulations include the Truth in Lending Act, the Truth in Savings Act, the Electronic Funds Transfer Act, the Expedited Funds Availability Act, the Equal Credit Opportunity Act, and the Fair Housing Act, among others. These laws and regulations mandate certain disclosure requirements and regulate the manner in which financial institutions must deal with customers when taking deposits or making loans to such customers. The Bank must comply with the applicable provisions of these consumer protection laws and regulations as part of their ongoing customer relations.

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The USA PATRIOT Act of 2001. The Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (“USA PATRIOT Act”) was enacted in October 2001. The USA PATRIOT Act is intended to strengthen U.S. law enforcement’s and the intelligence communities’ ability to work cohesively to combat terrorism on a variety of fronts. The potential impact of the USA PATRIOT Act on financial institutions of all kinds is significant and wide ranging. The USA PATRIOT Act contains sweeping anti-money laundering and financial transparency laws and requires various regulations, including: (i) due diligence requirements for financial institutions that administer, maintain, or manage private bank accounts or correspondent accounts for non-U.S. persons; (ii) standards for verifying customer identification at account opening; (iii) rules to promote cooperation among financial institutions, regulators and law enforcement entities in identifying parties that may be involved in terrorism or money laundering; (iv) reports by nonfinancial trades and business filed with the Treasury Department’s Financial Crimes Enforcement Network for transactions exceeding $10,000; and (v) filing of suspicious activities reports involving securities by brokers and dealers if they believe a customer may be violating U.S. laws and regulations.

Privacy. In addition to expanding the activities in which banks and bank holding companies may engage, the Gramm-Leach-Bliley Act also imposed new requirements on financial institutions with respect to customer privacy. The Gramm-Leach-Bliley Act generally prohibits disclosure of customer information to non-affiliated third parties unless the customer has been given the opportunity to object and has not objected to such disclosure. Financial institutions are further required to disclose their privacy policies to customers annually. Financial institutions, however, will be required to comply with state law if it is more protective of customer privacy than the Gramm-Leach-Bliley Act.

Legislative Initiatives

From time to time, various legislative and regulatory initiatives are introduced in Congress. Such initiatives may change banking statutes and the operating environment of the Company and its banking subsidiaries in substantial and unpredictable ways. The Company cannot determine the ultimate effect that any potential legislation, if enacted, or implementing regulations with respect thereto, would have, upon the financial condition or results of operations of the Company or its subsidiaries. A change in statutes, regulations or regulatory policies applicable to the Company or any of its subsidiaries could have a material effect on the financial condition, results of operations or business of the Company and its subsidiaries.

Enforcement Powers of Federal and State Banking Agencies

The federal banking agencies have broad enforcement powers, including the power to terminate deposit insurance, impose substantial fines and other civil and criminal penalties, and appoint a conservator or receiver. Failure to comply with applicable laws, regulations, and supervisory agreements could subject the Company or the Bank and their subsidiaries, as well as officers, directors, and other institution-affiliated parties of these organizations, to administrative sanctions and potentially substantial civil money penalties. In addition to the grounds discussed above under “—The Bank—Corrective Measures for Capital Deficiencies,” the appropriate federal banking agency may appoint the FDIC as conservator or receiver for a banking institution (or the FDIC may appoint itself, under certain circumstances) if any one or more of a number of circumstances exist, including, without limitation, the fact that the banking institution is undercapitalized and has no reasonable prospect of becoming adequately capitalized; fails to become adequately capitalized when required to do so; fails to submit a timely and acceptable capital restoration plan; or materially fails to implement an accepted capital restoration plan. The Texas Department of Banking also has broad enforcement powers over the Bank, including the power to impose orders, remove officers and directors, impose fines and appoint supervisors and conservators.

Effect on Economic Environment

The policies of regulatory authorities, including the monetary policy of the Federal Reserve Board, have a significant effect on the operating results of bank holding companies and their subsidiaries. Among the means

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available to the Federal Reserve Board to affect the money supply are open market operations in U.S. government securities, changes in the discount rate on member bank borrowings, and changes in reserve requirements against member bank deposits. These means are used in varying combinations to influence overall growth and distribution of bank loans, investments and deposits, and their use may affect interest rates charged on loans or paid for deposits.

Federal Reserve Board monetary policies have materially affected the operating results of commercial banks in the past and are expected to continue to do so in the future. The nature of future monetary policies and the effect of such policies on the business and earnings of the Company and its subsidiaries cannot be predicted.

ITEM 1A. RISK FACTORS

An investment in the Company’s Common Stock involves risks. The following is a description of the material risks and uncertainties that the Company believes affect its business and an investment in the Common Stock. Additional risks and uncertainties that the Company is unaware of, or that it deems immaterial, also may become important factors that affect the Company and its business. If any of the risks described in this annual report on Form 10-K were to occur, the Company’s financial condition and results of operations could be materially and adversely affected. If this were to happen, the value of the Common Stock could decline significantly and you could lose all or part of your investment.

Risks Associated with the Company’s Business

If the Company is not able to continue its historical levels of growth, it may not be able to maintain its historical earnings trends.

To achieve its past levels of growth, the Company has initiated internal growth programs and completed a number of acquisitions. The Company may not be able to sustain its historical rate of growth or may not even be able to grow at all. In addition, Prosperity may not be able to obtain the financing necessary to fund additional growth and may not be able to find suitable candidates for acquisition. Various factors, such as economic conditions and competition, may impede or prohibit the opening of new banking centers. Further, the Company may be unable to attract and retain experienced bankers, which could adversely affect its internal growth. If the Company is not able to continue its historical levels of growth, it may not be able to maintain its historical earnings trends.

If the Company is unable to manage its growth effectively, its operations could be negatively affected.

Companies that experience rapid growth face various risks and difficulties, including:

In addition, in order to manage its growth and maintain adequate information and reporting systems within its organization, the Company must identify, hire and retain additional qualified employees, particularly in the accounting and operational areas of its business.

If the Company does not manage its growth effectively, its business, financial condition, results of operations and future prospects could be negatively affected, and the Company may not be able to continue to implement its business strategy and successfully conduct its operations.

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If the Company is unable to identify and acquire other financial institutions and successfully integrate its acquired businesses, its business and earnings may be negatively affected.

The market for acquisitions remains highly competitive, and the Company may be unable to find acquisition candidates in the future that fit its acquisition and growth strategy. To the extent that the Company is unable to find suitable acquisition candidates, an important component of its growth strategy may be lost.

Acquisitions of financial institutions involve operational risks and uncertainties and acquired companies may have unforeseen liabilities, exposure to asset quality problems, key employee and customer retention problems and other problems that could negatively affect the Company’s organization. The Company may not be able to complete future acquisitions and, if completed, the Company may not be able to successfully integrate the operations, management, products and services of the entities that it acquires and eliminate redundancies. The integration process may also require significant time and attention from the Company’s management that they would otherwise direct at servicing existing business and developing new business. The Company’s failure to successfully integrate the entities it acquires into its existing operations may increase its operating costs significantly and adversely affect its business and earnings.

The Company’s business is subject to interest rate risk and fluctuations in interest rates may adversely affect its earnings and capital levels.

The majority of the Company’s assets are monetary in nature and, as a result, the Company is subject to significant risk from changes in interest rates. Changes in interest rates can impact the Company’s net interest income as well as the valuation of its assets and liabilities. The Company’s earnings are significantly dependent on its net interest income. Net interest income is the difference between the interest income earned on loans, investments and other interest-earning assets and the interest expense paid on deposits, borrowings and other interest-bearing liabilities. Therefore, any change in general market interest rates, such as a change in the monetary policy of the Federal Reserve or otherwise, can have a significant effect on the Company’s net interest income. The Company’s assets and liabilities may react differently to changes in overall market rates or conditions because there may be mismatches between the repricing or maturity characteristics of the assets and liabilities.

The Company’s profitability depends significantly on local economic conditions.

The Company’s success depends primarily on the general economic conditions of the geographic markets in which it operates. Unlike larger banks that are more geographically diversified, the Company provides banking and financial services to customers primarily in Houston, Dallas, Austin, Corpus Christi and surrounding areas and in the south and southeast areas of Texas. The local economic conditions in these areas have a significant impact on the Company’s commercial, real estate and construction loans, the ability of its borrowers to repay their loans and the value of the collateral securing these loans. A significant decline in general economic conditions, caused by inflation, recession, acts of terrorism, outbreak of hostilities or other international or domestic calamities, unemployment or other factors could impact these local economic conditions and negatively affect the Company’s financial results.

The Company’s allowance for credit losses may not be sufficient to cover actual credit losses, which could adversely affect its earnings.

As a lender, the Company is exposed to the risk that its loan customers may not repay their loans according to the terms of these loans and the collateral securing the payment of these loans may be insufficient to fully compensate the Company for the outstanding balance of the loan plus the costs to dispose of the collateral. The Company may experience significant loan losses which could have a material adverse effect on its operating results and financial condition. Management makes various assumptions and judgments about the collectibility of

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the Company’s loan portfolio, including the diversification by industry of its commercial loan portfolio, the amount of nonperforming loans and related collateral, the volume, growth and composition of its loan portfolio, the effects on the loan portfolio of current economic indicators and their probable impact on borrowers and the evaluation of its loan portfolio through its internal loan review process and other relevant factors.

The Company maintains an allowance for credit losses in an attempt to cover credit losses inherent in its loan portfolio. Additional credit losses will likely occur in the future and may occur at a rate greater than the Company has experienced to date. In determining the size of the allowance, the Company relies on an analysis of its loan portfolio, its experience and its evaluation of general economic conditions. If the Company’s assumptions prove to be incorrect, its current allowance may not be sufficient and adjustments may be necessary to allow for different economic conditions or adverse developments in its loan portfolio. Material additions to the allowance would materially decrease net income.

In addition, federal and state regulators periodically review the Company’s allowance for credit losses and may require the Company to increase its provision for credit losses or recognize further charge-offs, based on judgments different than those of the Company’s management. Any increase in the Company’s allowance for credit losses or charge-offs as required by these regulatory agencies could have a material adverse effect on the Company’s operating results and financial condition.

The Company’s small to medium-sized business target market may have fewer financial resources to weather a downturn in the economy.

The Company targets its business development and marketing strategy primarily to serve the banking and financial services needs of small to medium-sized businesses. These small to medium-sized businesses generally have fewer financial resources in terms of capital or borrowing capacity than larger entities. If general economic conditions negatively impact the southeast Texas area or the other markets in which the Company operates, the Company’s results of operations and financial condition may be negatively affected.

An interruption in or breach in security of the Company’s information systems may result in a loss of customer business.

The Company relies heavily on communications and information systems to conduct its business. Any failure or interruption or breach in security of these systems could result in failures or disruptions in the Company’s customer relationship management, general ledger, deposits, servicing or loan origination systems. Such interruptions may occur and may not be adequately addressed by the Company. The occurrence of any failures or interruptions could result in a loss of customer business and have a negative effect on the Company’s results of operations and financial condition.

The business of the Company is dependent on technology and its inability to invest in technological improvements may adversely affect its results of operations and financial condition.

The financial services industry is undergoing rapid technological changes with frequent introductions of new technology driven products and services. In addition to better serving customers, the effective use of technology increases efficiency and enables financial institutions to reduce costs. The Company’s future success will depend in part upon its ability to address the needs of its customers by using technology to provide products and services that will satisfy customer demands for convenience as well as create additional efficiencies in our operations. Many of the Company’s competitors have substantially greater resources to invest in technological improvements. The Company may not be able to effectively implement new technology driven products and services or be successful in marketing these products and services to its customers which may negatively affect the Company’s results of operations and financial condition.

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The Company operates in a highly regulated environment and, as a result, is subject to extensive regulation and supervision that could adversely affect its financial performance, and the Company may be adversely affected by changes in federal and local laws and regulations.

The Company is subject to extensive regulation, supervision and examination by federal and state banking authorities. Any change in applicable regulations or federal or state legislation could have a substantial impact on the Company, its subsidiary bank, and their respective operations. Additional legislation and regulations may be enacted or adopted in the future that could significantly affect the Company’s powers, authority and operations, or the powers, authority and operations of the Bank, which could have a material adverse effect on the Company’s financial condition and results of operations. Further, regulators have significant discretion and power to prevent or remedy unsafe or unsound practices or violations of laws by banks and bank holding companies in the performance of their supervisory and enforcement duties. The exercise of this regulatory discretion and power may have a negative impact on the Company.

Risks Associated with the Company’s Common Stock

The Company’s corporate organizational documents and the provisions of Texas law to which it is subject may delay or prevent a change in control of the Company that you may favor.

The Company’s amended and restated articles of incorporation and amended and restated bylaws contain various provisions which may delay, discourage or prevent an attempted acquisition or change of control of the Company. These provisions include:

The Company’s articles of incorporation provide for noncumulative voting for directors and authorize the board of directors to issue shares of its preferred stock without shareholder approval and upon such terms as the board of directors may determine. The issuance of the Company’s preferred stock could have the effect of making it more difficult for a third party to acquire, or of discouraging a third party from acquiring, a controlling interest in the Company. In addition, certain provisions of Texas law, including a provision which restricts certain business combinations between a Texas corporation and certain affiliated shareholders, may delay, discourage or prevent an attempted acquisition or change in control of the Company.

The holders of the Company’s junior subordinated debentures have rights that are senior to those of the Company’s shareholders.

As of December 31, 2005, the Company had $75.8 million in junior subordinated debentures outstanding that were issued to the Company’s subsidiary trusts. The subsidiary trusts purchased the junior subordinated debentures from the Company using the proceeds from the sale of trust preferred securities to third party investors. Payments of the principal and interest on the trust preferred securities are conditionally guaranteed by the Company to the extent not paid or made by each trust, provided the trust has funds available for such obligations.

The junior subordinated debentures are senior to the Company’s shares of Common Stock. As a result, the Company must make payments on the junior subordinated debentures (and the related trust preferred securities)

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before any dividends can be paid on its Common Stock and, in the event of the Company’s bankruptcy, dissolution or liquidation, the holders of the debentures must be satisfied before any distributions can be made to the holders of the Common Stock. The Company had the right to defer distributions on the junior subordinated debentures (and the related trust preferred securities) for up to five years, during which time no dividends may be paid to holders of the Company’s Common Stock.

Risks Related to the Company’s Acquisition of SNB Bancshares, Inc.

There may be undiscovered risks or losses associated with the SNB Bancshares acquisition.

As a result of the pending acquisition of SNB Bancshares, Inc., the Company will acquire all of the assets and liabilities of SNB Bancshares, including, without limitation, its loan portfolio. The Company has not previously owned or operated SNB Bancshares and it does not have any detailed working experience related to its business and operations. There may be instances when the Company, under its normal operating procedures, may find after the acquisition, that there may be additional losses or undisclosed liabilities with respect to the assets and liabilities of SNB Bancshares, and, with respect to its loan portfolio, that the ability of a borrower to repay a loan may have become impaired, the quality of the value of the collateral securing a loan may fall below the Company’s standards or the allowance for credit losses may not be adequate. One or more of these factors might cause the Company to have additional losses or liabilities, additional loan charge-offs or increases in allowances for credit losses, which could have a negative impact upon its future income.

The Company may not be able to successfully consummate the acquisition of SNB Bancshares. Even if the acquisition is consummated, the Company may not be able to integrate SNB Bancshares’ operations with its business efficiently.

While the Company has entered into a definitive agreement to acquire all of the capital stock of SNB Bancshares, there are a number of conditions to completing the acquisition, and there can be no assurance that those conditions will be satisfied. Even if the acquisition is consummated, it will create risks associated with the integration of SNB Bancshares’ operations with the Company’s, including, without limitation, the loss of key employees and customers, the disruption of ongoing businesses and possible inconsistencies in standards, controls and procedures.

The Company may not realize the benefits from the SNB Bancshares acquisition that it anticipates, or it may not be able to integrate SNB Bancshares’ operations successfully. If the Company fails to integrate the operations of SNB Bancshares efficiently, it could have a material adverse effect on the Company’s business, financial condition, results of operation and future prospects.

ITEM 1B. UNRESOLVED STAFF COMMENTS

None.

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ITEM 2. PROPERTIES

As of December 31, 2005, the Company conducted business at 85 full-service banking centers. The Company’s headquarters are located at Prosperity Bank Plaza, 4295 San Felipe, in the Galleria area in Houston, Texas. The Company owns all of the buildings in which its banking centers are located other than those listed below. The expiration dates of the leases for the banking centers listed below do not include optional renewal periods which may be available.

The following table sets forth specific information on each of the Company’s geographical market areas:

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ITEM 3. LEGAL PROCEEDINGS

Neither the Company nor the Bank is currently a party to any material legal proceeding.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

No matters were submitted to a vote of the Company’s security holders during the fourth quarter of 2005.

PART II.

ITEM 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED SHAREHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

The Company’s Common Stock began trading on November 12, 1998 and is listed on the Nasdaq National Market System under the symbol “PRSP”. Prior to that date, the Common Stock was privately held and not listed on any public exchange or actively traded. As of March 1, 2006, there were 27,864,894 shares outstanding and 876 shareholders of record. The number of beneficial owners is unknown to the Company at this time.

The following table presents the high and low intra-day sales prices for the Common Stock as reported on the Nasdaq National Market during the two years ended December 31, 2005:

Dividends

Holders of Common Stock are entitled to receive dividends when, as and if declared by the Company’s Board of Directors out of funds legally available therefor. While the Company has declared dividends on its Common Stock since 1994, and paid quarterly dividends aggregating $0.3475 per share in 2005 and $0.3075 per share in 2004, there is no assurance that the Company will continue to pay dividends in the future. Future dividends on the Common Stock will depend upon the Company’s earnings and financial condition, liquidity and capital requirements, the general economic and regulatory climate, the Company’s ability to service any equity or debt obligations senior to the Common Stock and other factors deemed relevant by the board of directors of the Company.

As a holding company, the Company is ultimately dependent upon its subsidiaries to provide funding for its operating expenses, debt service and dividends. Various banking laws applicable to the Bank limit the payment of dividends and other distributions by the Bank to the Company, and may therefore limit the Company’s ability to pay dividends on its Common Stock. If required payments on the Company’s outstanding junior subordinated debentures held by its unconsolidated subsidiary trusts are not made or suspended, the Company will be prohibited from paying dividends on its Common Stock. Regulatory authorities could impose administratively stricter limitations on the ability of the Bank to pay dividends to the Company if such limits were deemed appropriate to preserve certain capital adequacy requirements.

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The cash dividends declared per share by quarter (and paid on the first business day of the subsequent quarter) for the Company’s last two fiscal years were as follows:

Recent Sales of Unregistered Securities

None.

Securities Authorized for Issuance under Equity Compensation Plans

As of December 31, 2005, the Company had outstanding stock options granted under three stock option plans, all of which were approved by the Company’s shareholders. As of such date, the Company also had outstanding stock options granted under stock option plans that it assumed in connection with various acquisition transactions. The following table provides information as of December 31, 2005 regarding the Company’s equity compensation plans under which the Company’s equity securities are authorized for issuance:

Issuer Purchases of Equity Securities

None.

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ITEM 6. SELECTED CONSOLIDATED FINANCIAL DATA

The following selected consolidated financial data for, and as of the end of, each of the years in the five-year period ended December 31, 2005 are derived from and should be read in conjunction with the Company’s consolidated financial statements and the notes thereto. The historical consolidated financial data of the Company has been restated to include the accounts and operations of Commercial Bancshares, Inc. for all periods prior to February 23, 2001. All per share data for 2002 and 2001 has been restated to give effect to the two-for-one stock split effective May 31, 2002.

(Table continued on next page)

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ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Special Cautionary Notice Regarding Forward-Looking Statements

Statements and financial discussion and analysis contained in this annual report on Form 10-K that are not historical facts are forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are based on assumptions and involve a number of risks and uncertainties, many of which are beyond the Company’s control. Many possible events or factors could affect the future financial results and performance of the Company and could cause such results or performance to differ materially from those expressed in the forward-looking statements. These possible events or factors include, without limitation:

A forward-looking statement may include a statement of the assumptions or bases underlying the forward-looking statement. The Company believes it has chosen these assumptions or bases in good faith and that they are reasonable. However, the Company cautions you that assumptions or bases almost always vary from actual results, and the differences between assumptions or bases and actual results can be material.

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The Company undertakes no obligation to publicly update or otherwise revise any forward-looking statements, whether as a result of new information, future events or otherwise, unless the securities laws require the Company to do so.

Management’s Discussion and Analysis of Financial Condition and Results of Operations analyzes the major elements of the Company’s balance sheets and statements of income. This section should be read in conjunction with the Company’s consolidated financial statements and accompanying notes and other detailed information appearing elsewhere in this Annual Report on Form 10-K. The Commercial merger was accounted for as a pooling of interests and therefore the historical financial data of the Company has been restated to include the accounts and operations of Commercial for all periods prior to February 23, 2001.

For the Years Ended December 31, 2005, 2004 and 2003

Overview

The Company generates the majority of its revenues from interest income on loans, service charges on customer accounts and income from investment in securities. The revenues are partially offset by interest expense paid on deposits and other borrowings and non-interest expenses such as administrative and occupancy expenses. Net interest income is the difference between interest income on earning assets such as loans and securities and interest expense on liabilities such as deposits and borrowings which are used to fund those assets. Interest income is the Company’s largest source of revenue, representing 57.7% of total revenue during 2005. The level of interest rates and the volume and mix of earning assets and interest-bearing liabilities impact net interest income and margin. The Company has recognized increased net interest income due primarily to an increase in the volume of interest-earning assets.

Three principal components of the Company’s growth strategy are internal growth, stringent cost control practices and strategic merger transactions. The Company focuses on continual internal growth. Each banking center is operated as a separate profit center, maintaining separate data with respect to its net interest income, efficiency ratio, deposit growth, loan growth and overall profitability. Banking center presidents and managers are accountable for performance in these areas and compensated accordingly. The Company also focuses on maintaining stringent cost control practices and policies. The Company has invested significantly in the infrastructure required to centralize many of its critical operations, such as data processing and loan processing. Management believes that this centralized infrastructure can accommodate substantial additional growth while enabling the Company to minimize operational costs through certain economies of scale. The Company also intends to continue to seek expansion opportunities. During 2003, eleven banking centers were acquired in the Dallas/Fort Worth area. The acquisitions of Abrams and Dallas Bancshares were completed in May and June 2003, respectively, adding three banking centers in Dallas. The mergers with MainBancorp and FSBNT were completed in November and December 2003, respectively, adding an additional eight banking centers in Dallas. As a part of these acquisitions, two of the acquired banking centers were combined into existing banking centers nearby bringing the total to nine banking centers added in 2003. During 2004, seven banking centers were acquired in the Austin, Texas area, one of which was subsequently closed and consolidated into an existing banking center of the Company. The acquisitions of both Liberty Bancshares, Inc. (the “Liberty acquisition”) and Village Bank and Trust s.s.b. (the “Village acquisition”) were completed on August 1, 2004. During 2005, twenty seven (27) banking centers were acquired in the First Capital acquisition on March 1, 2005 and two (2) additional banking centers were acquired in the Grapeland acquisition on December 1, 2005.

Net income was $47.9 million, $34.7 million and $26.5 million for the years ended December 31, 2005, 2004 and 2003, respectively, and diluted earnings per share were $1.77, $1.59 and $1.36, respectively, for these same periods. Earnings growth during both 2005 and 2004 resulted principally from an increase in loan volume and acquisitions, including the Liberty and Village acquisitions in August 2004 and the First Capital acquisition in March 2005. Earnings growth during both 2004 and 2003 also resulted principally from an increase in loan

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volume and acquisitions, including the Abrams, Dallas Bancshares, MainBancorp, FSBNT, Liberty and Village acquisitions. The Company posted returns on average assets of 1.42%, 1.36% and 1.32% and returns on average equity of 11.56%, 14.27% and 15.60% for the years ended December 31, 2005, 2004 and 2003, respectively. The Company’s efficiency ratio was 48.91% in 2005, 49.23% in 2004 and 51.58% in 2003.

Total assets at December 31, 2005 and 2004 were $3.586 billion and $2.697 billion, respectively. Total deposits at December 31, 2005 and 2004 were $2.920 billion and $2.317 billion, respectively, with deposit growth in each period resulting from acquisitions and internal growth. Total loans were $1.542 billion at December 31, 2005, an increase of $506.6 million or 48.9% compared with $1.036 billion at December 31, 2004. At December 31, 2005, the Company had $1.1 million in nonperforming loans and its allowance for credit losses was $17.2 million. Shareholders’ equity was $464.7 million and $275.6 million at December 31, 2005 and 2004, respectively.

Critical Accounting Policies

The Company’s significant accounting policies are integral to understanding the results reported. The Company’s accounting policies are described in detail in Note 1 to the consolidated financial statements. The Company believes that of its significant accounting policies, the following may involve a higher degree of judgment and complexity:

Allowance for Credit Losses—The allowance for credit losses is a reserve established through charges to earnings in the form of a provision for credit losses. Management has established an allowance for credit losses which it believes is adequate for estimated losses in the Company’s loan portfolio. Based on an evaluation of the loan portfolio, management presents a monthly review of the allowance for credit losses to the Bank’s Board of Directors, indicating any change in the allowance since the last review and any recommendations as to adjustments in the allowance. In making its evaluation, management considers factors such as historical loan loss experience, industry diversification of the Company’s commercial loan portfolio, the amount of nonperforming assets and related collateral, the volume, growth and composition of the Company’s loan portfolio, current economic changes that may affect the borrower’s ability to pay and the value of collateral, the evaluation of the Company’s loan portfolio through its internal loan review process and other relevant factors. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off. Charge-offs occur when loans are deemed to be uncollectible. The allowance for credit losses includes allowance allocations calculated in accordance with Statement of Financial Accounting Standards (SFAS) No. 114, Accounting by Creditors for Impairment of a Loan, as amended by SFAS 118, and allowance allocations determined in accordance with SFAS No. 5, Accounting for Contingencies.

Goodwill—Goodwill and intangible assets that have indefinite useful lives are subject to at least an annual impairment test and more frequently if circumstances indicate their value may not be recoverable. Goodwill is tested for impairment using a two-step process that begins with an estimation of the fair value of each of the Company’s reporting units compared with its carrying value. If the carrying amount exceeds the fair value of a reporting unit, a second step test is completed comparing the implied fair value of the reporting unit’s goodwill to its carrying value to measure the amount of impairment. Intangible assets that are not amortized will be tested for impairment at least annually by comparing the fair values of those assets to their carrying values. Other identifiable intangible assets that are subject to amortization are amortized on an accelerated basis over the years expected to be benefited, which the Company believes is 8 years. These amortizable intangible assets are reviewed for impairment if circumstances indicate their value may not be recoverable based on a comparison of fair value to carrying value. Based on the Company’s annual goodwill impairment test as of September 30, 2005, management does not believe any of its goodwill is impaired as of December 31, 2005. While the Company believes no impairment existed at December 31, 2005 under accounting standards applicable at that date, different conditions or assumptions, or changes in cash flows or profitability, if significantly negative or unfavorable, could have a material adverse effect on the outcome of the Company’s impairment evaluation and financial condition or future results of operations.

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Stock-based Compensation—The Company adopted the provisions of SFAS No. 123R “Share-Based Payment (Revised 2004),” on January 1, 2006. The Company had previously adopted SFAS No. 123 on January 1, 2003. Among other things, SFAS No. 123R eliminates the ability to account for stock-based compensation using the intrinsic value based method of accounting and requires that such transactions be recognized as compensation expense in the income statement based on their fair values on the date of the grant. SFAS No. 123R requires that management make assumptions including stock price volatility and employee turnover that are utilized to measure compensation expense. The fair value of stock options granted is estimated at the date of grant using the Black-Scholes option-pricing model. This model requires the input of highly subjective assumptions.

Results of Operations

Net Interest Income

The Company’s operating results depend primarily on its net interest income, which is the difference between interest income on interest-earning assets, including securities and loans, and interest expense incurred on interest-bearing liabilities, including deposits and other borrowed funds. Interest rate fluctuations, as well as changes in the amount and type of earning assets and liabilities, combine to affect net interest income. The Company’s net interest income is affected by changes in the amount and mix of interest-earning assets and interest-bearing liabilities, referred to as a “volume change.” It is also affected by changes in yields earned on interest-earning assets and rates paid on interest-bearing deposits and other borrowed funds, referred to as a “rate change.”

The Company adopted FIN 46R, “Consolidation of Variable Interest Entities” on January 1, 2004. FIN 46R requires that Prosperity Statutory Trust II, Prosperity Statutory Trust III, Prosperity Statutory Trust IV, Paradigm Capital Trust II (fully redeemed on February 28, 2006), First Capital Statutory Trust I and First Capital Statutory Trust II be deconsolidated from the consolidated financial statements. Accordingly, the trust preferred securities issued by each of the foregoing trusts are no longer shown in the consolidated financial statements. Instead, the junior subordinated debentures issued by the Company to each of these trusts are shown as liabilities in the consolidated balance sheets and interest expense associated with such junior subordinated debentures is shown as interest expense in the consolidated statements of income. The dividend expense associated with the trust preferred securities for the year ended December 31, 2003 was previously shown as noninterest expense. Prior period data has been restated to reflect the adoption of FIN 46R.

2005 versus 2004. Net interest income before the provision for credit losses for the year ended December 31, 2005 was $110.9 million compared with $82.0 million for the year ended December 31, 2004, an increase of $28.9 million or 35.3%. The improvement in net interest income for 2005 was principally due to an increase in average interest-earning assets to $2.949 billion at December 31, 2005 from $2.302 billion at December 31 2004, an increase of $647.7 million or 28.1%. The increase in average interest-earning assets was primarily due to the First Capital acquisition. The improvement in net interest income for 2005 was also partially due to an increase in the yield on interest-earning assets that was greater than the increase in the rate paid on interest-bearing liabilities. Total cost of interest-bearing liabilities increased 57 basis points from 1.64% for the year ended December 31, 2004 to 2.21% for the year ended December 31, 2005, while total yield on interest-earning assets increased 64 basis points from 4.86% at December 31, 2004 to 5.50% at December 31, 2005. At December 31, 2005, period end demand deposits represented an important component of funding sources and was 23.1% of total period end deposits compared with 22.4% at December 31, 2004.

Net interest margin (not on a tax equivalent basis), defined as net interest income divided by average interest-earning assets, for 2005 was 3.76%, up 20 basis points from 3.56% in 2004. The increase in the net interest margin was primarily attributable to an increase in interest-earning assets.

2004 versus 2003. Net interest income before the provision for credit losses for the year ended December 31, 2004 was $82.0 million compared with $64.5 million for the year ended December 31, 2003, an

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increase of $17.5 million or 27.1%. The improvement in net interest income for 2004 was principally due to an increase in average interest-earning assets to $2.302 billion at December 31, 2004 from $1.830 billion at December 31 2003, an increase of $471.3 million or 25.8%. The improvement in net interest income for 2004 was also partially due to a decrease in the rate paid on interest-bearing liabilities that was greater than the decrease in the yield on interest-earning assets. Total cost of interest-bearing liabilities decreased 15 basis points from 1.79% for the year ended December 31, 2003 to 1.64% for the year ended December 31, 2004 while total yield on interest-earning assets decreased 10 basis points from 4.96% at December 31, 2003 to 4.86% at December 31, 2004. At December 31, 2004, period end demand deposits averaged 22.4% of total period end deposits in 2004 compared with 22.4% in 2003.

Net interest margin (not on a tax equivalent basis) for 2004 was 3.56%, up four basis points from 3.52% in 2003. The increase in the net interest margin was primarily attributable to an increase in interest-earning assets.

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The following table presents for the periods indicated the total dollar amount of average balances, interest income from average interest-earning assets and the resultant yields, as well as the interest expense on average interest-bearing liabilities, expressed both in dollars and rates. Except as indicated in the footnotes, no tax-equivalent adjustments were made and all average balances are daily average balances. Any nonaccruing loans have been included in the table as loans carrying a zero yield.

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