As filed with the Securities and Exchange Commission on December 22, 1999 SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8 - K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 DATE OF REPORT - DECEMBER 22, 1999 Commission Registrant, State of Incorporation I.R.S. Employer File Number Address and Telephone Number Identification No. - ----------- ------------------------------------- ------------------ 0-25595 NIAGARA MOHAWK HOLDINGS, INC. 16-1549726 (a New York corporation) 300 Erie Boulevard West Syracuse, New York 13202 Telephone 315-474-1511 1-2987 NIAGARA MOHAWK POWER CORPORATION 15-0265555 (a New York corporation) 300 Erie Boulevard West Syracuse, New York 13202 Telephone 315-474-1511 Item 5. Other Events - --------------------- (a) On December 22, 1999, Niagara Mohawk Power Corporation issued a press release regarding Rochester Gas & Electric Corporation's decision to exercise its right of first refusal with respect to Niagara Mohawk's announced sale of its nuclear generating assets to AmerGen Energy Company, LLC. (Exhibit No. 99) Item 7. Financial Statements and Exhibits - ------------------------------------------ Exhibits - Following is the list of Exhibits furnished in accordance with the provisions of Item 601 of Regulation S-K, filed as part of this current report on Form 8-K. Exhibit No. 99 - Press release regarding Rochester Gas & Electric Corporation's decision to exercise its right of first refusal with respect to Niagara Mohawk's announced sale of its nuclear generating assets to AmerGen Energy Company, LLC. NIAGARA MOHAWK HOLDINGS, INC. AND SUBSIDIARY COMPANIES SIGNATURE --------- Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrants have duly caused this report to be signed on their behalf by the undersigned thereunto duly authorized. NIAGARA MOHAWK HOLDINGS, INC. ----------------------------- (Registrant) Date: December 22, 1999 By: /s/Steven W. Tasker ---------------------------- Steven W. Tasker Vice President-Controller and Principal Accounting Officer, in his respective capacities as such NIAGARA MOHAWK POWER CORPORATION --------------------------------- (Registrant) Date: December 22, 1999 By: /s/Steven W. Tasker ----------------------------- Steven W. Tasker Vice President-Controller and Principal Accounting Officer, in his respective capacities as such EXHIBIT INDEX ------------- Following is the index of Exhibits furnished in accordance with the provisions of Item 601 of Regulation S-K, filed as part of this current report on Form 8-K. Exhibit No. 99 - Press release regarding Rochester Gas & Electric Corporation's decision to exercise its right of first refusal with respect to Niagara Mohawk's announced sale of its nuclear generating assets to AmerGen Energy Company, LLC.