UNITIL CORP - Annual Report: 2006 (Form 10-K)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K

For the fiscal year ended December 31, 2006

OR

Commission file number 1-8858

UNITIL CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (603) 772-0775

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

Securities registered pursuant to Section 12(g) of the Act: NONE

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 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.

Large Accelerated filer  ¨        Accelerated filer  x        Non-accelerated filer  ¨

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 this Form 10-K or any amendments to this Form 10-K  x

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

Based on the closing price of June 30, 2006, the aggregate market value of common stock held by non-affiliates of the registrant was $132,492,742.

The number of common shares outstanding of the registrant was 5,660,619 as of February 21, 2007.

Documents Incorporated by Reference:

Portions of the Proxy Statement relating to the Annual Meeting of Shareholders to be held April 19, 2007, are incorporated by reference into Part III of this Report

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UNITIL CORPORATION

FORM 10-K

For the Fiscal Year Ended December 31, 2006

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PART I

UNITIL CORPORATION

Unitil Corporation (Unitil or the Company) is a public utility holding company. Unitil was incorporated under the laws of the State of New Hampshire in 1984. The following companies are wholly-owned subsidiaries of Unitil:

Unitil and its subsidiaries are subject to regulation as a holding company system by the Federal Energy Regulatory Commission (FERC) under the Energy Policy Act of 2005. Prior to the passage of the Energy Policy Act of 2005, Unitil and its subsidiaries were subject to regulation as a registered holding company system under the Public Utility Holding Company Act of 1935 (PUHCA) by the Securities and Exchange Commission (SEC). As a result of the enactment of the Energy Policy Act of 2005, PUHCA has been repealed.

Unitil’s principal business is the retail distribution of electricity in the southeastern seacoast and capital city areas of New Hampshire and the retail distribution of both electricity and natural gas in the greater Fitchburg area of north central Massachusetts. Unitil has two distribution utility subsidiaries, UES, which operates in New Hampshire and FG&E, which operates in Massachusetts (collectively referred to as the “retail distribution utilities”). Unitil’s retail distribution utilities serve approximately 99,300 electric customers and 15,000 natural gas customers in their franchise areas. The retail distribution companies are local “pipes and wires” utility distribution companies with a combined investment in net utility plant of $231.8 million at December 31, 2006. Unitil’s total revenue was $260.9 million in 2006. Earnings applicable to common shareholders for 2006 was $7.9 million. Substantially all of Unitil’s revenue and earnings are derived from regulated utility operations.

A third utility subsidiary, Unitil Power, formerly functioned as the full requirements wholesale power supply provider for UES. In connection with the implementation of electric industry restructuring in New Hampshire, Unitil Power ceased being the wholesale supplier of UES on May 1, 2003 and divested of substantially all of its long-term power supply contracts through the sale of the entitlements to the electricity associated with those contracts.

Unitil also has three other wholly-owned subsidiaries: Unitil Service, Unitil Realty and Unitil Resources. Unitil Service provides, at cost, a variety of administrative and professional services, including regulatory, financial, accounting, human resources, engineering, operations, technology and management services on a centralized basis to its affiliated Unitil companies. Unitil Realty owns and manages the Company’s corporate office in Hampton, New Hampshire and leases this facility to Unitil Service under a long-term lease arrangement. Unitil Resources is the Company’s wholly-owned non-regulated subsidiary. Usource, Inc. and Usource L.L.C. (collectively, Usource) are wholly-owned subsidiaries of Unitil Resources. Usource provides energy brokering and advisory services to large commercial and industrial customers in the northeastern United States.

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OPERATIONS

Electric Utility Operations

Unitil’s electric utility operations are conducted through the retail distribution utilities, UES and FG&E. Revenue from Unitil’s electric utility operations was $225.2 million for 2006. Earnings from electric utility operations were $7.0 million for the same 12-month period.

The primary business of Unitil’s electric utility operations is the local distribution of electricity to customers in its franchise areas. As a result of the implementation of retail choice in New Hampshire and Massachusetts, Unitil’s customers are free to contract for their supply of electricity with third-party suppliers. The retail distribution utilities continue to deliver that supply of electricity over their distribution systems. Both UES and FG&E supply electricity to those customers who do not obtain their supply from third-party suppliers, with the costs associated with electricity supplied by the Company being recovered on a pass-through basis under periodically-adjusted rates.

UES distributes electricity to approximately 71,600 customers in New Hampshire in the capital city of Concord as well as 12 surrounding towns and all or part of 16 towns in the southeastern and seacoast regions of New Hampshire, including the towns of Hampton, Exeter, Atkinson and Plaistow. UES’ franchise areas consist of approximately 408 square miles. The state capital of New Hampshire is located within UES’ franchise areas, and includes the executive, legislative and judicial branches and offices and facilities for all major state government services as well as several federal government facilities. In addition, UES’ franchise areas are retail trading and recreation centers for the central and southeastern parts of the state. These areas serve diversified commercial and industrial businesses, including manufacturing firms engaged in the production of electronic components, wires and plastics. UES’ franchise areas include popular resort areas and beaches along the Atlantic Ocean, including the Hampton Beach recreational area. UES’ 2006 retail electric operating revenue was $155.8 million, of which approximately 45.0% was derived from residential sales and 55.0% from commercial/industrial sales.

FG&E is engaged in the retail distribution of both electricity and natural gas in the city of Fitchburg and several surrounding communities. FG&E’s franchise area encompasses approximately 170 square miles. Electricity is supplied and distributed by FG&E to approximately 27,700 customers in the communities of Fitchburg, Ashby, Townsend and Lunenburg. FG&E’s industrial customers include paper manufacturing and paper products companies, rubber and plastics manufacturers, chemical products companies and printing, publishing and associated industries. FG&E’s 2006 retail electric operating revenue was $69.4 million, of which approximately 46.0% was derived from residential sales and 54.0% from commercial/industrial sales.

Gas Utility Operations

Natural gas is supplied and distributed by FG&E to approximately 15,000 retail customers in the communities of Fitchburg, Lunenburg, Townsend, Ashby, Gardner and Westminster, all located in Massachusetts.

As a result of the introduction of retail choice for all natural gas customers in Massachusetts, FG&E’s customers are free to contract for their supply of natural gas with third-party suppliers. FG&E continues to provide natural gas supply services to those customers who do not obtain their supply from third-party suppliers. The costs associated with natural gas supplied by FG&E are recovered on a pass-through basis under periodically adjusted rates.

FG&E’s 2006 gas operating revenue was $33.3 million, of which approximately 51.0% was derived from residential firm sales and 49.0% from commercial/industrial firm sales. Earnings from FG&E’s gas utility operations were $0.5 million for 2006.

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Seasonality

Natural gas sales in New England are seasonal, and the Company’s results of operations reflect this seasonal nature. Accordingly, results of operations are typically positively impacted by gas operations during the five heating season months, from November through March. Electric sales in New England are far less seasonal than natural gas sales; however, the highest usage typically occurs in both the summer due to air conditioning demand and the winter months due to heating-related requirements and shorter daylight hours.

Non-regulated and Other Non-Utility Operations

Unitil’s non-regulated operations are conducted through Unitil Resources and its subsidiary Usource. Usource provides energy brokering and consulting services to large commercial and industrial customers in the northeastern United States. Revenue from Unitil’s non-regulated operations was $2.4 million in 2006. Earnings from Unitil’s non-regulated operations was a net loss of ($0.2 million) in 2006. Unitil’s other non-utility subsidiaries include Unitil Service and Unitil Realty, which provide centralized facilities, management and administrative services to Unitil’s affiliated companies. Unitil’s consolidated net income includes the earnings of the holding company and these subsidiaries. The earnings of these other non-utility operations are principally derived from income earned on short-term investments and real property owned for Unitil’s and its subsidiaries’ use and is reported in Other segment income (for segment information, see Part II, Item 8, Note 10 herein). Net earnings from Unitil’s other non-utility operations was $0.6 million in 2006.

(For details on Unitil’s Results of Operations, see Part II, Item 7 herein.)

RATES AND REGULATION

Unitil and its subsidiaries are subject to regulation as a holding company system by the FERC under the Energy Policy Act of 2005 in regards to certain bookkeeping, accounting and reporting requirements. Unitil’s utility operations related to wholesale and interstate energy business activities are also regulated by FERC. The retail distribution utilities, UES and FG&E, are subject to regulation by the New Hampshire Public Utilities Commission (NHPUC) and the Massachusetts Department of Telecommunications and Energy (MDTE), respectively, in regards to their rates, issuance of securities and other accounting and operational matters. Because Unitil’s primary operations are subject to rate regulation, the regulatory treatment of various matters could significantly affect the Company’s operations and financial position.

Unitil’s retail distribution utilities have the franchise to deliver electricity and/or natural gas to all customers in their franchise areas, at rates established under traditional cost of service regulation. Under this regulatory structure, UES and FG&E recover the cost of providing distribution service to their customers based on a historical test year, in addition to earning a return on their capital investment in utility assets. As a result of a restructuring of the utility industry in Massachusetts and New Hampshire, Unitil’s customers have the opportunity to purchase their electric or natural gas supplies from third party vendors. Most customers, however, continue to purchase such supplies through UES and FG&E as the provider of last resort. UES and FG&E purchase electricity or natural gas from unaffiliated wholesale suppliers and recover the actual costs of these supplies on a pass-through basis, as well as certain costs associated with industry restructuring, through reconciling rate mechanisms that are periodically adjusted.

In connection with the implementation of retail choice, Unitil Power and FG&E divested substantially all of their long-term power supply contracts and interests in generation assets through the sale of the interest in those assets or the sale of the entitlements to the electricity provided by those generation assets and long-term power supply contracts. UES and FG&E recover in their rates all the costs associated with the divestiture of their power supply portfolios and have secured regulatory approval from the NHPUC and MDTE, respectively, for the recovery of power supply-related stranded costs and other restructuring-related

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regulatory assets. The remaining balance of these assets, to be recovered principally over the next four to six years, is $126.1 million as of December 31, 2006 and is included in Regulatory Assets on the Company’s Consolidated Balance Sheet (see Regulatory Assets table in Note 1.) Unitil’s retail distribution companies have a continuing obligation to submit filings in both states that demonstrate their compliance with regulatory mandates and provide for timely recovery of costs in accordance with their approved restructuring plans.

ELECTRIC POWER SUPPLY

The transition to retail choice required the divestiture of Unitil’s existing power supply arrangements and the procurement of replacement supplies, which provided the flexibility for migration of customers to and from utility service. FG&E, UES, and Unitil Power each are members of the New England Power Pool (NEPOOL) and participate in the Independent System Operator—New England (ISO-NE) markets for the purpose of facilitating these wholesale electric power supply transactions, which are necessary to serve Unitil’s retail customers.

Unitil’s customers in both New Hampshire and Massachusetts now have the opportunity to purchase their electric supply from competitive retail suppliers. Retail choice has been successful for Unitil’s largest customers. As of December 2006, 45% of Unitil’s largest New Hampshire customers representing 18% of total New Hampshire electric sales and 87% of Unitil’s largest Massachusetts customers representing 42% of total Massachusetts electric sales are purchasing their electric power supply in the competitive market. However, most residential and small commercial customers continue to purchase their electric supply through the retail distribution utilities. The concentration of the competitive retail market on higher use customers has been a common experience throughout the New England electricity market.

Regulated Energy Supply

In order to provide regulated electric supply as the provider of last resort to their respective retail customers, the retail distribution companies enter into wholesale electric power supply contracts with various wholesale suppliers.

FG&E has power supply contracts with various wholesale suppliers for the provision of Default Service. MDTE policy dictates the pricing structure and duration of each of these contracts. Currently, all Default Service power supply contracts for large general accounts are three months in duration. Default Service power supply contracts for residential and small and medium general service customers are acquired every 6 months, with each 12 month contract providing 50% of the class requirements. The MDTE is investigating alternatives to the current procurement policy for all accounts, other than the large general accounts. This process could potentially lead to the procurement of FG&E Default Service power supply for longer durations in order to provide more price stability for smaller customers throughout Massachusetts for whom competitive retail options are relatively scarce.

UES currently has power supply contracts with various wholesale suppliers for the provision of Default Service to its customers. UES procures Default Service for its largest general service accounts through successive competitive solicitations of three-months duration and procures Default Service for all other customers through a series of two one-year contracts and two three-year contracts with each contract covering 25% of the total requirements of the group. The first two contracts were of 6-months and 18-months duration in order to stagger the start dates of future 1-year and 3-year procurements.

Regional Transmission and Power Markets

FG&E, UES and Unitil Power, as well as virtually all New England electric utilities, are participants in ISO New England Inc., the Regional Transmission Organization (RTO) in New England. The regional bulk

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power system is operated by an independent corporate entity, ISO-NE. The purpose of ISO-NE is to assure reliable operation of the bulk power system in the most economic manner for the region. Substantially all operation and dispatching of electric generation and bulk transmission capacity in New England is performed on a regional basis. The Tariff imposes generating capacity and reserve obligations, and provides for the use of major transmission facilities and support payments associated therewith. The most notable benefits of the ISO-NE are coordinated power system operation in a reliable manner and a supportive business environment for the development of a competitive electric marketplace. The formation of an RTO and other wholesale market changes are not expected to have a material impact on Unitil’s operations because of the cost recovery mechanisms for wholesale energy and transmission costs approved by the MDTE and NHPUC.

GAS SUPPLY

FG&E’s natural gas customers now have the opportunity to purchase their natural gas supply from third-party suppliers, though most customers continue to purchase such supplies at regulated rates through FG&E as the provider of last resort. The costs associated with the acquisition of such wholesale natural gas supplies for customers who do not contract with third-party suppliers are recovered on a pass-through basis through periodically-adjusted rates and are included in Purchased Gas in the Consolidated Statements of Earnings.

FG&E purchases natural gas from domestic and Canadian suppliers under contracts of one year or less, as well as from producers and marketers on the spot market and arranges for the transportation to its distribution facilities under long-term contracts with the Tennessee interstate pipeline. FG&E has a four-year contract for liquefied natural gas (LNG) supply ending in 2008, which was approved by the MDTE. The following tables summarize actual gas purchases by source of supply and the cost of gas sold for the years 2004 through 2006.

Sources of Gas Supply

(Expressed as percent of total MMBtu of gas purchased)

FG&E has available under firm contract 14,057 MMbtu per day of year-round and seasonal transportation and underground storage capacity to its distribution facilities. As a supplement to pipeline natural gas, FG&E owns a propane air gas plant and a LNG storage and vaporization facility. These plants are used principally during peak load periods to augment the supply of pipeline natural gas.

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ENVIRONMENTAL MATTERS

The Company’s past and present operations include activities that are generally subject to extensive federal and state environmental laws and regulations. The Company believes it is in compliance with all applicable environmental and safety laws and regulations, and the Company believes that as of December 31, 2006, there are no material losses reasonably possible in excess of recorded amounts. However, there can be no assurance that significant costs and liabilities will not be incurred in the future. It is possible that other developments, such as increasingly stringent federal, state or local environmental laws and regulations could result in increased environmental compliance costs.

Sawyer Passway MGP Site—FG&E continues to work with environmental regulatory agencies to identify and assess environmental issues at the former manufactured gas plant (MGP) site at Sawyer Passway, located in Fitchburg, Massachusetts. FG&E has proceeded with site remediation work as specified on the Tier 1B permit issued by the Massachusetts Department of Environmental Protection (DEP), which allows FG&E to work towards temporary closure of the site. A status of temporary closure requires FG&E to monitor the site until a feasible permanent remediation alternative can be developed and completed.

FG&E has recovered the environmental response costs incurred at this former MGP site in gas rates pursuant to an MDTE approved settlement agreement between the Massachusetts Attorney General and the natural gas utilities of the Commonwealth of Massachusetts (Agreement). The Agreement allows FG&E to amortize and recover environmental response costs from gas customers over succeeding seven-year periods, without carrying costs. In addition FG&E has filed suit against several of its former insurance carriers seeking coverage for past and future environmental response costs at the site. Any recovery that FG&E receives from insurance or third parties with respect to environmental response costs, net of the unrecovered costs associated therewith, are split equally between FG&E and its gas customers.

FG&E is in the process of developing long range plans for a feasible permanent remediation solution for the Sawyer Passway site, including alternatives for re-use of the site. Included on the Company’s Consolidated Balance Sheet at December 31, 2006 in Environmental Obligations is $12.0 million related to estimated future costs for permanent remediation of the site. A corresponding regulatory asset was recorded to reflect the future rate recovery for these costs. The amounts recorded do not assume any amounts are recoverable from insurance companies or other third parties.

The Company’s ultimate liability for future environmental remediation costs may vary from estimates, which may be adjusted as new information or future developments become available. Based on the Company’s current assessment of its environmental responsibilities, existing legal requirements and regulatory policies, the Company does not believe that these environmental costs will have a material adverse effect on the Company’s consolidated financial position or results of operations.

EMPLOYEES

As of December 31, 2006, the Company and its subsidiaries had 304 employees. The Company considers its relationship with employees to be good and has not experienced any major labor disruptions.

There are approximately 100 employees represented by labor unions. These employees are covered by collective bargaining agreements, which expire May 31, 2010. The agreements provide discreet salary adjustments, established work practices and uniform benefit packages. The Company expects to successfully negotiate new agreements prior to their expiration dates.

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AVAILABLE INFORMATION

The Company’s Internet address is www.unitil.com. There, the Company makes available, free of charge, its SEC fillings, including annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and other reports, as well as amendments to those reports. These reports are made available through the Investors section of Unitil’s website via a direct link to the section of the SEC’s website which contains Unitil’s SEC filings.

The Company’s current Code of Ethics was approved by Unitil’s Board of Directors on January 15, 2004. This Code of Ethics, along with any amendments or waivers, is also available on Unitil’s website.

Unitil’s common stock is listed on the American Stock Exchange under the ticker symbol “UTL.”

DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

The following table provides information about our directors and senior management as of February 21, 2007:

Robert G. Schoenberger has been Unitil’s Chairman of the Board and Chief Executive Officer since 1997 and Unitil’s President since 2003. Prior to his employment with Unitil, he was President and Chief Executive Officer of the New York Power Authority (a state owned public power enterprise) from 1993 until 1997. He is also a Trustee and Chairman of Exeter Health Resources.

Mark H. Collin has been Unitil’s Senior Vice President and Chief Financial Officer since February 2003. Mr. Collin has served as Unitil’s Treasurer since 1998. Since 1992, he has been Treasurer of UES and FG&E. Mr. Collin joined Unitil in 1988. Mr. Collin serves on the Board of Governors of New Hampshire Public Television.

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Thomas P. Meissner, Jr. has been Unitil’s Senior Vice President and Chief Operating Officer since June 2005. Mr. Meissner served as Unitil’s Senior Vice President, Operations from February 2003 through June 2005. Mr. Meissner joined Unitil in 1994 and served as Unitil’s Director of Engineering from 1998 to 2003. From 1985 to 1994, he was employed by the Public Service Company of New Hampshire.

Laurence M. Brock has been Unitil’s Chief Accounting Officer and Controller since June 2005. Mr. Brock joined Unitil in 1995 as Vice President and Controller, and is a Certified Public Accountant in the State of New Hampshire. Prior to his employment with Unitil, Mr. Brock served as a Corporate Controller with a group of diversified financial services and manufacturing companies. Mr. Brock gained his public accounting experience with Coopers & Lybrand in Boston, Massachusetts.

Todd R. Black has been President of Usource since June 2003. He served as Vice President, Sales and Marketing for Usource from 1998 to 2003. Prior to his employment with Unitil, he served as Vice President, Services Delivery for Energy USA, the non-regulated subsidiary of Bay State Gas Company, from 1988 until 1998.

George R. Gantz has been Unitil’s Senior Vice President, Customer Services and Communications since January 2003. Mr. Gantz previously served as Unitil’s Senior Vice President, Communication and Regulation from 1994 to 2003. Mr. Gantz joined Unitil in 1983.

George E. Long, Jr. has been Unitil’s Vice President, Administration since February 2003. Mr. Long joined Unitil in 1994 and was Director, Human Resources from 1998 to 2003. Prior to his employment with Unitil, Mr. Long was the Director of Compensation and Benefits at Monarch Life Insurance Company from 1985 to 1994.

Raymond J. Morrissey has been Unitil’s Vice President, Information Systems since February 2003. From 1992 to 2003, he served as Unitil’s Vice President of Customer Service, and from 1991 to 1992, he was the General Manager of Unitil’s subsidiary, FG&E. Mr. Morrissey joined Unitil in 1985.

Sandra L. Whitney has been Unitil’s Corporate Secretary and Secretary of the Board since February 2003. Ms. Whitney has been the Corporate Secretary of Unitil’s subsidiary companies, FG&E, UES, Unitil Power, Unitil Realty and Unitil Service since 1994. Ms. Whitney joined Unitil in 1990.

Dr. Robert V. Antonucci has been President of Fitchburg State College since 2003. Dr. Antonucci was also President of the School Group of Riverdeep, Inc. from 2001 to 2003, and President and CEO of Harcourt Learning Direct and Harcourt Online College from 1998 to 2001. Dr. Antonucci also served as the Commissioner of Education for the Commonwealth of Massachusetts from 1992 to 1998. Dr. Antonucci also serves as a Director of Eastern Bank.

David P. Brownell was a Senior Vice President of Tyco International Ltd. from 1995 until his retirement in 2003. He had been with Tyco since 1984. Mr. Brownell is also Interim President of the University of New Hampshire Foundation.

Michael J. Dalton was Unitil’s President and Chief Operating Officer from 1984 until his retirement in 2003. Mr. Dalton is a member of the Industrial Advisory Board of the University of New Hampshire College of Engineering and Physical Sciences.

Albert H. Elfner, III was the Chairman, from 1994, and Chief Executive Officer, from 1995, of Evergreen Investment Management Company until his retirement in 1999. Mr. Elfner is also a Director of NGM Insurance Company (NGM), as well as a member of the NGM Finance Committee.

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Edward F. Godfrey was the Executive Vice President and Chief Operating Officer of Keystone Investments, Incorporated from 1997 until his retirement in 1998. While at Keystone Investments, he was also a Senior Vice President, Chief Financial Officer and Treasurer from 1988 to 1996. Mr. Godfrey is also a Director of VehiCare, LLC since 2006.

Michael B. Green has been the President and Chief Executive Officer of Capital Region Health Care and Concord Hospital since 1992. Mr. Green is also a member of the Adjunct Faculty, Dartmouth Medical School, Dartmouth College. He also currently serves on the Board of the Foundation for Healthy Communities, is a Director and Chair of the New Hampshire Hospital Association, a Director of New Hampshire Business Committee for the Arts, a Director of Merrimack County Savings Bank, including membership on the bank’s Investment and Audit Committees, and a member of the Concord Monitor Board of Contributors.

Eben S. Moulton has been the Managing Partner of Seacoast Capital Corporation since 1995. Mr. Moulton is also a Director of IEC Electronics, a Director of six private companies and a Trustee of Colorado College.

M. Brian O’Shaughnessy has been the Chairman of the Board, Chief Executive Officer and President of Revere Copper Products, Inc. since 1988. Mr. O’Shaughnessy also serves on the Board of Directors of the National Association of Manufacturers, the International Copper Association, the Copper Development Association, and the Copper and Brass Fabricators Council. He also serves in New York State as Chairman of the Industrial Energy Consumer Coalition, and as a member of the Board of Directors of the Multiple Intervenors.

Charles H. Tenney, III has been Director of Operations for Brainshift.com, Inc. since 2002. He also served as a financial advisor for H&R Block Financial Advisors from 2001 to 2002. Mr. Tenney also served on the Board of Overseers of the Huntington Theater Company, Boston, Massachusetts from 2004 – 2006.

Dr. Sarah P. Voll has been the Vice President, National Economic Research Associates, Inc. (NERA) since 1999. Dr. Voll was also a Senior Consultant at NERA from 1996 to 1999. Prior to her employment with NERA, Dr. Voll was a staff member at the New Hampshire Public Utilities Commission from 1980 – 1996.

INVESTOR INFORMATION

Annual Meeting

The annual meeting of shareholders is scheduled to be held at the offices of the Company, 6 Liberty Lane West, Hampton, New Hampshire, on Thursday, April 19, 2007, at 10:30 a.m.

Transfer Agent

The Company’s transfer agent, Computershare, is responsible for shareholder records, issuance of stock certificates, and the distribution of Unitil’s dividends and IRS Form 1099-DIV. Shareholders may contact Computershare at:

Computershare

P.O. Box 43078

Providence, RI 02940-3078

Telephone: 800-736-3001

www.computershare.com

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Investor Relations

For information about the Company and your investment, you may call the Company directly, toll-free, at: 800-999-6501 and ask for the Investor Relations Representative; visit the Investor page at www.unitil.com; or contact the transfer agent, Computershare, at the number listed above.

Special Services & Shareholder Programs Available

To enroll, please contact the Company’s Investor Relations Representative or Computershare.

To enroll, please contact the Company’s Investor Relations Representative or Computershare.

For information, please contact Computershare at 800-935-9330 or the Company’s Investor Relations Representative at 800-999-6501.

Risks Relating to Our Business

Risks related to the regulation of our business could impact the rates we are able to charge, our costs and our profitability.

We are subject to comprehensive regulation by federal and state regulatory authorities, which significantly influences our operating environment and our ability to recover costs from our customers. In particular, we are regulated by the FERC and state regulatory authorities with jurisdiction over public utilities, including the NHPUC and the MDTE. These authorities regulate many aspects of our operations, including, but not limited to, construction and maintenance of facilities, operations, safety, issuance of securities, accounting matters, transactions between affiliates, the rates that we can charge customers and the rate of return that we are allowed to realize. Our ability to obtain rate adjustments to maintain our current rate of return depends upon regulatory action under applicable statutes, rules and regulations, and we cannot assure you that we will be able to obtain rate adjustments or continue receiving our current authorized rates of return. These regulatory authorities are also empowered to impose financial penalties and other sanctions on us if we are found to have violated statutes and regulations governing our utility operations.

We are unable to predict the impact on our operating results from the regulatory activities of any of these agencies. Although we have attempted to actively manage the rate making process and have had recent success in obtaining rate increases, we can offer no assurances as to future success in the rate making process. Despite our requests, these regulatory commissions have authority under applicable statutes, rules and regulations to leave our rates unchanged, grant increases or order decreases in such rates. They have similar authority with respect to the recovery of our electricity and natural gas supply costs incurred by UES and FG&E in their role as a “provider of last resort” for customers who do not contract with third-party suppliers, or whose third-party supplier fails to deliver. In the event that we are unable to recover these costs or recovery of these costs were to be significantly delayed, our operating results could be materially adversely affected. Changes in regulations or the imposition of additional regulations could also have an adverse effect on our operating results.

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As a result of industry restructuring, we have a significant amount of certain stranded energy supply costs, which are subject to recovery in future periods.

The stranded costs resulting from the implementation of industry restructuring mandated by the states of New Hampshire and Massachusetts are recovered by us on a pass-through basis through periodically adjusted rates. Any unrecovered balance of purchased power or stranded costs is deferred for future recovery as a regulatory asset. Such regulatory assets are subject to periodic regulatory review and approval for recovery in future periods.

Our power supply portfolio related stranded costs due to the electric industry restructuring in New Hampshire and Massachusetts for which regulatory approval has been obtained for recovery were approximately $50.0 million for FG&E and $42.6 million for UES as of December 31, 2006 (See total of $92.6 million on the Power Supply Buyout Obligations line of Regulatory Assets table of Note 1). Substantially all of FG&E’s stranded costs relate to owned generation assets and power purchase agreements divested by FG&E under a long-term contract buy-out agreement. Approximately $18.4 million of UES’ stranded costs are attributable to the long-term power purchase agreements divested by Unitil Power under a long-term contract buyout agreement. Because FG&E and Unitil Power remain ultimately responsible for purchase power payments underlying these long-term buyout agreements, FG&E and Unitil Power could incur additional stranded costs were they required to resell such divested entitlements prior to the end of their term for amounts less than the amounts agreed to under the existing long-term buyout agreements. We expect that any such additional stranded costs would be recovered from our customers, although such recovery would require approval from the MDTE or NHPUC, the receipt of which cannot be assured.

Our electric and natural gas sales and revenues are highly correlated with the economy, and national, regional and local economic conditions may negatively impact our customers and correspondingly our operating results and financial condition.

Our business is influenced by the economic activity of our franchise areas. The level of economic growth in our electric and natural gas distribution franchise areas directly affects our potential for future growth in our business. As a result, adverse changes in the economy may have negative effects on our revenues, operating results and financial condition.

Declines in the valuation of capital markets could require us to make substantial cash contributions to cover our pension obligations, which could negatively impact our financial condition. In addition, the recovery of certain pension obligations is subject to regulatory risks.

We made a voluntary cash contribution to our pension plan of $2.0 million in 2004. In 2005, we were required to make a minimum cash contribution of $0.7 million to our pension plan and made an additional voluntary cash contribution of $1.8 million for a total of $2.5 million. In 2006, we were required and made a minimum cash contribution of $2.5 million to our pension plan. If the valuation of capital markets were to significantly decline from current levels, we may be required to make cash contributions to our pension plans substantially in excess of the levels currently anticipated, which could adversely affect our financial condition.

On August 17, 2006, the Pension Protection Act of 2006 (PPA) was signed into law. Included in the PPA are new minimum funding rules which will go into effect for plan years beginning in 2008. The funding target will be 100% of a plan’s liability with any shortfall amortized over seven years, with lower (92% – 100%) funding targets available to well-funded plans during the transition period.

In September 2006, the Financial Accounting Standards Board (FASB) issued FASB Statement No. 158, “Employers’ Accounting for Defined Benefit Pension and Other Postretirement Plans”, (SFAS No. 158), an amendment of SFAS No. 87, “Employers’ Accounting for Pensions”, SFAS No. 88, “Employers’ Accounting for Settlements and Curtailments of Defined Benefit Pension Plans and for

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Termination Benefits,” SFAS No. 106, “Employers’ Accounting for Postretirement Benefits other than Pensions” and SFAS No. 132(R), “Employers’ Disclosures about Pensions and Other Postretirement Benefits.” SFAS No. 158 requires companies to record on their balance sheets as an asset or liability the overfunded or underfunded status of their retirement benefit obligations (RBO) based on the projected benefit obligation. The Company has recognized a corresponding Regulatory Asset, to recognize the future collection of these obligations in electric and gas retail rates. In the event that we are unable to recover these costs or recovery of these costs were to be significantly delayed, our operating results could be materially adversely affected. See Note 8 also.

Increases in interest rates could have a negative impact on our financial condition.

Our utility subsidiaries have ongoing capital expenditure requirements which they frequently fund by issuing short and long-term debt. Changes in interest rates do not affect interest expense associated with presently outstanding fixed rate long-term debt securities. However, changes in interest rates may affect the interest rate and corresponding interest expense on any new long-term debt securities that are issued. In addition, short-term debt borrowings are typically at variable rates of interest. As a result, changes in short-term interest rates will increase or decrease our interest expense associated with short-term borrowings. Increases in interest rates generally will increase our borrowing costs and could adversely affect our financial condition or results of operations.

Weather conditions may cause our sales to vary from year to year.

Our utility operating sales vary from year to year, depending on weather conditions. We estimate that approximately 75% of our annual natural gas sales are temperature sensitive. As a result, mild winter temperatures can cause a decrease in the amount of gas we sell in any year, particularly during the winter heating season. Our electric sales are generally less sensitive to weather than our gas sales, but may also be affected by weather conditions in both the winter and summer seasons.

We are a holding company and have no operating income of our own. Our ability to pay dividends on our common stock is dependent on dividends received from our subsidiaries and on factors directly affecting us, the parent corporation. We cannot assure you that our current annual dividend will be paid in the future.

We are a public utility holding company and we do not have any operating income of our own. Consequently, our ability to pay dividends on our common stock is dependent on dividends and other payments received from our subsidiaries, principally UES and FG&E. The ability of our subsidiaries to pay dividends or make distributions to us will depend on, among other things:

In addition, we may incur indebtedness in the future. Before we can pay dividends on our common stock, we have to satisfy our debt obligations and comply with any statutory or contractual limitations.

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Our current annual dividend is $1.38 per share of common stock, payable quarterly. However, our board of directors reviews our dividend policy periodically in light of the factors referred to above, and we cannot assure you of the amount of dividends, if any, that may be paid in the future.

Transporting and storing natural gas and supplemental gas supplies, as well as electricity, involve numerous risks that may result in accidents and other operating risks and costs.

Inherent in our electric and gas distribution activities are a variety of hazards and operating risks, such as leaks, explosions, electrocutions and mechanical problems that could cause substantial financial losses. In addition, these risks could result in loss of human life, significant damage to property, environmental pollution, and impairment of our operations and substantial losses to us. In accordance with customary industry practice, we maintain insurance against some, but not all, of these risks and losses. The location of pipelines, storage facilities and electric distribution equipment near populated areas, including residential areas, commercial business centers and industrial sites, could increase the level of damages resulting from these risks. The occurrence of any of these events not fully covered by insurance could adversely affect our financial position and results of operations.

Our business is subject to environmental regulation in all jurisdictions in which we operate and our costs of compliance are significant. Any changes in existing environmental regulation and the incurrence of environmental liabilities could negatively affect our results of operations and financial condition.

Our utility operations are generally subject to extensive federal, state and local environmental laws and regulations relating to air quality, water quality, waste management, natural resources and the health and safety of our employees. Failure to comply with these laws and regulations may result in the assessment of administrative, civil, and criminal penalties; imposition of remedial requirements; and even issuance of injunctions to ensure future compliance. Liability under certain environmental laws is strict, joint and several in nature. Although we believe we are in general compliance with all applicable environmental and safety laws and regulations, there can be no assurance that significant costs and liabilities will not be incurred in the future. Moreover, it is possible that other developments, such as increasingly stringent federal, state or local environmental laws and regulations, could result in increased environmental compliance costs. See “Environmental Matters” in the Part I, Item 1, and Note 5 of this report for further detail.

Catastrophic events could have a material adverse effect on our financial condition or results of operations.

The electric and natural gas utility industries are from time to time affected by catastrophic events, such as unusually severe weather and significant and widespread failures of plant and equipment. Other catastrophic occurrences, such as terrorist attacks on utility facilities, may occur in the future. Such events could have a material adverse effect on us, since they could inhibit our ability to continue providing electric and/or gas distribution services to our customers for an extended period, which is the principal source of our operating income.

Customers’ future performance under multi-year energy brokering contracts.

The Company’s non-regulated energy brokering business provides energy brokering and consulting services to large commercial and industrial customers in the northeastern United States. Revenues from this business are primarily derived from brokering fees and charges billed to suppliers as customers take delivery of energy from these suppliers under term contracts. The Company cannot guarantee customers’ future performance under multi-year energy brokering contracts.

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None.

As of December 31, 2006, Unitil owned, through its retail distribution utilities: two operation centers, approximately 2,155 pole miles of local transmission and distribution overhead electric lines and 518 conduit bank miles of underground electric distribution lines, along with 59 electric substations, including three mobile electric substations. FG&E’s natural gas operations property includes a liquid propane gas plant, a liquid natural gas plant and 317 miles of underground gas mains. In addition, Unitil’s real estate subsidiary, Unitil Realty, owns the Company’s corporate headquarters building and the 12 acres on which it is located.

UES owns and maintains distribution operations centers in Concord, New Hampshire and Kensington, New Hampshire. UES’ 37 electric distribution substations, including a 5,000 kilovolt ampere (kVA) mobile substation, constitute 257,315 kVA of capacity (includes spares and mobile) for the transformation of electric energy from the 34.5 kV sub-transmission voltage to other primary distribution voltage levels. The electric substations are located on land owned by UES or occupied by UES pursuant to a perpetual easement.

UES has a total of approximately 1,598 pole miles of local transmission and distribution overhead electric lines and a total of 342 conduit bank miles of underground electric distribution lines. The electric distribution lines are located in, on or under public highways or private lands pursuant to lease, easement, permit, municipal consent, tariff conditions, agreement or license, expressed or implied through use by UES without objection by the owners. In the case of certain distribution lines, UES owns only a part interest in the poles upon which its wires are installed, the remaining interest being owned by telephone companies.

Additionally, UES owns 139.2 acres of non-utility property located on the east bank of the Merrimack River in Concord, New Hampshire. Of the total acreage, 81.2 acres are located within an industrial park zone.

The physical utility properties of UES, with certain exceptions, and its franchises are pledged as security under its indenture of mortgage and deed of trust under which the respective series of first mortgage bonds of UES are outstanding.

FG&E’s electric properties consist principally of 557 pole miles of local transmission and distribution overhead electric lines, 176 conduit bank miles of underground electric distribution lines and 22 transmission and distribution stations including two mobile electric substations. The capacity of these substations totals 662,650 kVA.

FG&E owns a liquid propane gas plant and a liquid natural gas plant and the land on which they are located. FG&E also has 317 miles of underground steel, cast iron and plastic gas mains.

FG&E’s electric substations, with minor exceptions, are located on land owned by FG&E or occupied by FG&E pursuant to a perpetual easement. FG&E’s electric distribution lines and gas mains are located in, on or under public highways or private lands pursuant to lease, easement, permit, municipal consent, tariff conditions, agreement or license, expressed or implied through use by FG&E without objection by the owners. FG&E leases its distribution operations center located in Fitchburg, Massachusetts.

The Company believes that its facilities are currently adequate for their intended uses.

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The Company is involved in legal and administrative proceedings and claims of various types, which arise in the ordinary course of business. Certain specific matters are discussed in Note 5 to the Consolidated Financial Statements. The Company believes, based upon information furnished by counsel and others, the ultimate resolution of these claims will not have a material impact on the Company’s financial position.

None

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PART II

The Registrant’s Common Stock is traded on the American Stock Exchange. As of December 31, 2006, there were 1,389 Common Shareholders of record.

Common Stock Data

Information regarding Securities Authorized for Issuance Under Equity Compensation Plans is set forth in the table below.

EQUITY COMPENSATION PLAN BENEFIT INFORMATION

NOTES: (also see Note 2 to the Consolidated Financial Statements)

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Stock Performance Graph

The following graph compares Unitil Corporation’s cumulative stockholder return since December 31, 2001 with the Peer Group index, comprised of the S&P Utility Index, and the S&P 500 index. The graph assumes that the value of the investment in the Company’s common stock and each index (including reinvestment of dividends) was $100 on December 31, 2001.

Comparative Five-Year Total Returns

NOTES:

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Unregistered Sales of Equity Securities and Uses of Proceeds

(a) There were no sales of unregistered equity securities by the Company for the fiscal period ended December 31, 2006.

(b) Not applicable.

(c) Issuer repurchases are shown in the table below for the monthly periods noted:

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OVERVIEW

Unitil Corporation (Unitil or the Company) is a public utility holding company. Unitil’s principal business is the retail distribution of electricity and natural gas through two utility subsidiaries: Unitil Energy System’s Inc. (UES) and Fitchburg Gas and Electric Light Company (FG&E). UES is an electric utility with an operating franchise in the southeastern seacoast and capital city areas of New Hampshire. FG&E is a combination gas and electric utility with an operating franchise in the greater Fitchburg area of north central Massachusetts.

Unitil’s two retail distribution utilities serve approximately 99,300 electric customers and 15,000 natural gas customers in their franchise areas. The retail distribution companies are local “pipes and wires” utilities with a combined investment in net utility plant of $231.8 million at December 31, 2006. Unitil’s total revenue was $260.9 million in 2006. Earnings applicable to common shareholders for 2006 was $7.9 million. Substantially all of Unitil’s revenue and earnings are derived from regulated utility operations.

Unitil also conducts non-regulated operations principally through its Usource subsidiary. Usource provides energy brokering and consulting services to large commercial and industrial customers in the northeastern United States. Usource’s total revenues were $2.4 million in 2006. Unitil’s other subsidiaries include Unitil Service and Unitil Realty, which provide centralized facilities, management and administrative services to Unitil’s affiliated companies. Unitil’s consolidated net income includes the earnings of the holding company and these subsidiaries.

CAUTIONARY STATEMENT

This report and the documents we incorporate by reference into this report contain statements that constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, included or incorporated by reference into this report, including, without limitation, statements regarding the financial position, business strategy and other plans and objectives for the Company’s future operations, are forward-looking statements.

These statements include declarations regarding the Company’s beliefs and current expectations. In some cases, forward-looking statements can be identified by terminology such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of such terms or other comparable terminology. These forward-looking statements are subject to inherent risks and uncertainties in predicting future results and conditions that could cause the actual results to differ materially from those projected in these forward-looking statements. Some, but not all, of the risks and uncertainties include the following:

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Many of these risks are beyond the Company’s control. Any forward-looking statements speak only as of the date of this report, and the Company undertakes no obligation to update any forward-looking statements to reflect events or circumstances after the date on which such statements are made or to reflect the occurrence of unanticipated events. New factors emerge from time to time, and it is not possible for the Company to predict all of these factors, nor can the Company assess the impact of any such factor on its business or the extent to which any factor, or combination of factors, may cause results to differ materially from those contained in any forward-looking statements.

See also Item 1A. Risk Factors.

RESULTS OF OPERATIONS

The following section of MD&A compares the results of operations for each of the three fiscal years ended December 31, 2006, 2005 and 2004 and should be read in conjunction with the accompanying Consolidated Financial Statements and the accompanying Notes to Consolidated Financial Statements included in Item 8 of this report.

Net Income and EPS Overview

The Company’s Earnings Applicable to Common Shareholders (Net Income) was $7.9 million for 2006. Earnings per common share were $1.41 for 2006 compared to $1.51 for 2005. Earnings in 2006 reflect lower electric and gas sales. The lower sales in 2006 were primarily driven by milder weather compared to 2005. Earnings in 2006 also reflect higher operating and maintenance expenses and interest costs. Partially offsetting these factors was an increase in electric distribution rates in 2006 for Unitil’s utility subsidiary in New Hampshire and increased gas delivery sales under a new contract with a large industrial customer in Massachusetts.

During the fourth quarter of 2006, the Company received final approval of a rate settlement that increased base distribution rates by about $3.1 million on an annualized basis for its electric utility operations in New Hampshire. The Company also recently received approval of a gas base rate settlement in Massachusetts for its gas distribution operations, which will phase-in rate increases of $1.2 million as of February 1, 2007, and an additional $1.0 million increase on November 1, 2007. Together these rate settlements represent an increase of about 10% on Unitil’s consolidated electric and gas distribution revenues.

Total electric sales decreased 2.2% in 2006 compared to 2005. This decrease reflects significantly milder weather in 2006 and overall lower average monthly energy usage by customers.

Total sales of natural gas increased 8.6% in 2006 compared to 2005, primarily due to a new transportation sales contract with a large industrial customer. Absent the sales from this new contract, total gas sales were approximately 10.7% lower in 2006 compared to 2005. These lower gas sales also reflect the significantly milder winter weather in 2006. The weather in the Company’s service territories in the winter of 2006 was approximately 12% warmer than in the same period for 2005, reflecting a record warm winter heating season.

Total electric and gas sales margin decreased $1.3 million in 2006 compared to 2005. The decline in average energy usage by customers, which was primarily driven by milder weather, negatively impacted total electric and gas sales margin by $1.7 million. This negative impact on electric and gas sales margin was partially offset by $0.4 million, net, due to changes in electric rates in 2006 compared to 2005, gas delivery sales under a new transportation contract with a large industrial customer, and higher revenues from Usource.

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Total Operations & Maintenance expense increased $1.2 million in 2006 compared to 2005. This increase reflects higher retiree and employee benefit costs of $0.8 million, higher salaries and compensation expenses of $0.7 million and an increase in all other operating expenses of $0.2 million, net, partially offset by lower outside services expenses and professional fees of $0.5 million.

Depreciation, Amortization, Taxes and Other decreased $2.8 million in 2006 compared to 2005, due to lower amortization on regulatory assets and lower utility plant depreciation rates resulting from the New Hampshire rate settlement, partially offset by increased depreciation on utility plant additions and higher property and payroll taxes.

Interest Expense, Net increased $1.1 million in 2006 compared to 2005 due to higher borrowings and interest rates compared to last year.

Usource, our non-regulated energy brokering business, recorded revenues of $2.4 million in 2006, an increase of $0.4 million over 2005. Usource’s revenues are primarily derived from fees and charges billed to suppliers as customers take delivery of energy from these suppliers under term contracts brokered by Usource. The Company will also realize future fees estimated at the end of December 2006 of $6.0 million from executed energy supply term contracts running from 2007 through 2011.

The Company’s Net Income was $8.4 million for 2005, an increase of $0.4 million, or 4.8%, compared to 2004. Earnings per common share were $1.51 for 2005, an increase of $0.06 per share compared with earnings of $1.45 per share for 2004. Compared to 2004, earnings for 2005 reflect higher electric sales, driven by customer growth and hotter summer weather in 2005, and higher gas sales reflecting a new contract with a large industrial customer.

In 2006, Unitil’s annual common dividend was $1.38, representing an unbroken record of quarterly dividend payments since trading began in Unitil’s common stock. At its January, 2007 meeting, the Unitil Board of Directors declared a quarterly dividend on the Company’s common stock of $0.345 per share.

A more detailed discussion of the Company’s 2006 results of operations and a year-to-year comparison of changes in financial position are presented below.

Balance Sheet

The Company’s investment in Net Utility Plant increased by $18.5 million in 2006 compared to 2005. This increase was due to capital expenditures related to UES’ and FG&E’s electric and gas distribution systems and expenditures of approximately $7.3 million for the Company’s Advanced Metering Infrastructure (AMI) project. AMI involves the integration of communication technology with metering technology to facilitate two-way communication between the utility and customer equipment. This technology is designed to provide more frequent, time-based metering information, enabling the recording and retrieval of interval metering data on at least an hourly basis.

Regulatory Assets increased $19.1 million in 2006 compared to 2005, primarily reflecting the recording of Regulatory Assets for Retirement Benefit Obligations in accordance with newly issued Federal Accounting Standards Board (FASB) Statement No. 158, “Employers’ Accounting for Defined Benefit Pension and Other Postretirement Plans”, (SFAS No. 158) (See Note 8) and the recording of a Regulatory Asset for future environmental remediation obligations associated with the Company’s former manufactured gas plant site at Sawyer Passway, located in Fitchburg, Massachusetts (See Note 5), partially offset by a decrease in Regulatory Assets related to current year cost recoveries.

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Long-Term Debt increased $14.7 million in 2006 compared to 2005 reflecting the issuance and sale on September 26, 2006 by UES of $15.0 million of Series O 6.32% First Mortgage Bonds, due September 15, 2036, to institutional investors in the form of a private placement.

Deferred Income Taxes decreased $17.8 million in 2006 compared to 2005 primarily reflecting the recording of deferred tax assets related to Retirement Benefit Obligations, discussed below.

Retirement Benefit Obligations increased $38.4 million in 2006 compared to 2005 primarily reflecting the recording of pension, PBOP and SERP obligations.

Environmental Obligations increased $12.0 million in 2006 compared to 2005 reflecting the recording of a liability for future environmental remediation obligations associated with the Company’s former manufactured gas plant site at Sawyer Passway, discussed above.

Sales

Kilowatt-hour Sales—The following table details total kWh sales for the last three years by major customer class:

Unitil’s total kWh sales decreased 2.2% in 2006 compared to 2005. This decrease reflects a decline in average energy usage per customer, primarily due to significantly milder weather. The weather in the Company’s service territories in the winter of 2006 was approximately 12% warmer than in the same period for 2005, resulting in lower consumption of electricity for heating related purposes. During the summer of 2006 the weather in the Company’s service territories was approximately 11% cooler than in the same period for 2005, resulting in lower consumption of electricity for air conditioning purposes.

Unitil’s total kWh sales increased 2.8% in 2005 compared to 2004. This increase reflects growth in sales to residential and commercial customers primarily due to hotter summer weather and an increase in the number of customers served in 2005 than in 2004.

Therm Sales—The following table details total firm therm sales for the last three years, by major customer class:

Unitil’s total firm therm sales of natural gas increased 8.6% in 2006 compared to 2005, due to a new gas transportation sales contract with a large industrial customer. Sales to residential customers decreased 10.9% in 2006 compared to 2005 due to a milder winter heating season in 2006 compared to the prior year.

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Sales to C&I customers increased 24.8% in 2006 compared to 2005. Absent the sales from the new contract, discussed above, sales to C&I customers were 10.4% lower in 2006 compared to 2005 primarily due to a milder winter heating season. The weather in the Company’s service territories in the winter of 2006 was approximately 12% warmer than in the same period for 2005, and the region as a whole experienced a record warm winter heating season.

In 2005, total firm therm sales of natural gas increased 5.2% compared to 2004, due to the new sales contract with a large industrial customer, discussed above. Sales to residential customers decreased 2.7% in 2005 compared to 2004 due to a milder winter heating season in 2005 compared to the prior year. Sales to C&I customers increased 12.7% in 2005 compared to 2004. Absent the sales from the new contract discussed above, sales to C&I customers were 3.4% lower in 2005 compared to 2004 due to lower natural gas usage by our largest customers.

Utility Revenues and Margin

Electric Operating Revenues—The following table details total Electric Operating Revenue and Sales Margin for the last three years by major customer class:

Total Electric Operating Revenues increased by $27.9 million, or 14.1%, in 2006 compared to 2005. Total Electric Operating Revenues include the recovery of costs of electric sales, which are recorded as Purchased Electricity and Conservation & Load Management (C&LM) in Operating Expenses. The net increase in Total Electric Operating Revenues in 2006 reflects higher Purchased Electricity costs of $29.2 million, offset by lower sales margin of $1.1 million and lower C&LM revenues of $0.2 million.

Purchased Electricity and C&LM revenues increased a net $29.0 million, or 14.7%, of Total Electric Operating Revenues in 2006 compared to 2005, reflecting higher electric commodity prices. Purchased Electricity revenues include the recovery of the cost of electric supply as well as other energy supply related restructuring costs, including long-term power supply contract buyout costs. C&LM revenues include the recovery of the cost of energy efficiency and conservation programs. The Company recovers the cost of Purchased Electricity and C&LM in its rates at cost on a pass through basis.

Electric sales margin was lower by $1.1 million in 2006 compared to 2005, reflecting a decrease in revenue of $3.2 million related to the expiration of the Seabrook Amortization Surcharge (SAS) in late 2005. This decrease in SAS revenue is largely matched with a corresponding decrease in amortization expenses on Regulatory Assets, and therefore has no material impact on net income (see discussion on Depreciation and Amortization below). Absent the decrease in SAS revenues, electric sales margin increased $2.1 million in 2006 compared to 2005. The higher sales margin in 2006 primarily reflects the

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Company’s recently approved base rate increase in New Hampshire of $2.7 million, partially offset by lower sales margin of $0.6 million resulting from a decline in average energy usage per customer, primarily due to significantly milder weather.

In 2005, Total Electric Operating Revenues increased by $13.4 million, or 7.3%, compared to 2004. The net increase in Total Electric Operating Revenues in 2005 reflects higher Purchased Electricity costs of $12.2 million and higher C&LM revenues of $0.3 million and higher sales margin of $0.9 million. Purchased Electricity and C&LM revenues increased a combined $12.5 million, or 6.8%, of Total Electric Operating Revenues in 2005 compared to 2004, reflecting higher electricity unit sales and higher electric commodity prices and increased spending on energy efficiency programs. Electric sales margin increased by $0.9 million in 2005 compared to 2004, primarily reflecting increased kWh unit sales and higher base rates, partially offset by the expiration of the SAS in 2005, as discussed above.

Gas Operating Revenues—The following table details total Gas Operating Revenue and Margin for the last three years by major customer class: