SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K/A [ X ] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 1999 OR [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission file number 1-8858 UNITIL CORPORATION (Exact name of registrant as specified in its charter) New Hampshire 02-0381573 (State or other jurisdiction of (I.R.S. Employer incorporation or organization) Identification No.) 6 Liberty Lane West, Hampton, New Hampshire 03842-1720 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (603) 772-0775 Securities registered pursuant to Section 12(b) of the Act: Title of Each Class Name of Exchange on Which Registered Common Stock, No Par Value American Stock Exchange Securities registered pursuant to Section 12(g) of the Act: NONE 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 this Form 10-K or any amendments to this Form 10-K [ X ] Based on the closing price of March 1, 2000, the aggregate market value of common stock held by non-affiliates of the registrant was $152,713,587. The number of common shares outstanding of the registrant was 4,717,022 as of March 1, 2000. Documents Incorporated by Reference: Portions of the Proxy Statement relating to the Annual Meeting of Shareholders to be held April 20, 2000, are incorporated by reference into Part III of this Report. This Amendment reflects the addition of the Report of Independent Certified Public Accountants to Part II, Item 8 of Form 10-K for the fiscal year ended December 31, 1999. The report was inadvertently omitted from the original 10-K filing on March 30, 2000. SIGNATURE Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. 						Unitil Corporation Date April 13, 2000 By /s/ Anthony J. Baratta, Jr. Anthony J. Baratta, Jr. Executive Vice President and Chief Financial Officer Report of Independent Certified Public Accountants To the Shareholders of Unitil Corporation: We have audited the accompanying consolidated balance sheets and consolidated statements of capitalization of Unitil Corporation and subsidiaries as of December 31, 1999 and 1998, and the related consolidated statements of earnings, cash flows and changes in common stock equity for each of the three years in the period ended December 31, 1999. These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits in accordance with auditing standards generally accepted in the United States. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe our audits provide a reasonable basis for our opinion. In our opinion, the financial statements referred to above present fairly, in all material respects, the consolidated financial position of Unitil Corporation and subsidiaries as of December 31, 1999 and 1998, and the consolidated results of their operations and their consolidated cash flows for each of the three years in the period ended December 31, 1999, in conformity with accounting principles generally accepted in the United States. We have also audited Schedule VIII of Unitil Corporation and subsidiaries as of December 31, 1999 and for the three years then ended included in Part IV Item 14. In our opinion, the schedule presents fairly, in all material respects, the information required to be set forth therein. GRANT THORNTON LLP Boston, Massachusetts February 7, 2000