UNITIL CORP

UNITIL CORPORATION In this Annual Report on Form 10-K, the Company , Unitil , we , and our refer to Unitil Corporation and its subsidiaries, unless the context requires otherwise. Unitil is a public utility holding company incorporated under the laws of the State of New Hampshire in 1984. The following companies are wholly-owned subsidiaries of Unitil: Company Name State and Year of Organization Principal Business Unitil Energy Systems, Inc. (Unitil Energy) NH - 1901 Electric Distribution Utility Fitchburg Gas and Electric Light Company (Fitchburg) MA - 1852 Electric & Natural Gas Distribution Utility Northern Utilities, Inc. (Northern Utilities) NH - 1979 Natural Gas Distribution Utility Bangor Natural Gas Company (Bangor) ME - 1998 Natural Gas Distribution Utility Maine Natural Gas Corporation (Maine Natural) ME - 1998 Natural Gas Distribution Utility Granite State Gas Transmission, Inc. (Granite State) NH - 1955 Natural Gas Transmission Pipeline Unitil Power Corp. (Unitil Power) NH - 1984 Wholesale Electric Power Utility Unitil Service Corp. (Unitil Service) NH - 1984 Utility Service Company Unitil Realty Corp. (Unitil Realty) NH - 1986 Real Estate Management Unitil Resources, Inc. (Unitil Resources) NH - 1993 Non-regulated Energy Services Unitil Water Corp. (Unitil Water) NH - 2025 Non-regulated Company 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.