As filed with the Securities and Exchange Commission on May 15, 2000

                       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 - MAY 12, 2000



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 May 12, 2000, Niagara Mohawk Power Corporation issued a press release
     regarding the termination of its June 24, 1999 agreement with AmerGen
     Energy Co. to sell its ownership of Nine Mile Point Units 1 and 2 nuclear
     plants (Exhibit No. 99-1).

(b)  On May 12, 2000, Niagara Mohawk Power Corporation issued a press
     release relating to the closing on the sale of its Albany oil and
     gas-fired electric generation station.  See press release attached
     (Exhibit No. 99-2).

(c)  On May 12, 2000, Niagara Mohawk Power Corporation closed on the
     issuance of $200 million, 8-7/8 percent series senior notes due May
     15, 2007.  The senior notes will have an effective rate of 8.919 percent
     and are optionally redeemable in whole or in part at any time.

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. 99-1 - Press release issued on May 12, 2000 regarding the
termination of its June 24, 1999 agreement with AmerGen Energy Co. to sell its
ownership of Nine Mile Point Units 1 and 2 nuclear plants.

Exhibit No. 99-2 - Press release issued on May 12, 2000 by Niagara Mohawk Power
Corporation relating to the closing on the sale of its Albany oil and gas-fired
electric generation station.




             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:  May 15, 2000               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:  May 15, 2000               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. 99-1 - Press release issued on  May 12, 2000 regarding the
termination of its June 24, 1999 agreement with AmerGen Energy Co. to sell its
ownership of Nine Mile Point Units 1 and 2 nuclear plants.

Exhibit No. 99-2 - Press release issued on May 12, 2000 by Niagara Mohawk Power
Corporation relating to the closing on the sale of its Albany oil and gas-fired
electric generation station.