SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SC TO-T/A SC 13E3/A (Amendment No. 1) TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934. NIAGARA MOHAWK POWER CORPORATION (Name of Subject Company (Issuer)) NATIONAL GRID GROUP PLC (Name of Filing Person) Fixed/AdjustableRate Cumulative Preferred Stock, Series D Cumulative Preferred Stock, 3.40% Series Cumulative Preferred Stock, 3.60% Series Cumulative Preferred Stock, 3.90% Series Cumulative Preferred Stock, 4.10% Series Cumulative Preferred Stock, 4.85% Series Cumulative Preferred Stock, 5.25% Series (Title of Class of Securities) 653522771 653522201 653522300 653522409 653522508 653522607 653522706 (CUSIP Number of Class of Securities) Gregory Barone John Cochrane Niagara Mohawk Power Corporation National Grid USA 300 Erie Boulevard West 25 Research Drive Syracuse, NY 13202 Westborough, MA 01582 (Names and addresses of persons authorized to receive notices and communications on behalf of the person filing statement) Copy to: Keith F. Higgins, Esq. Ropes & Gray One International Place Boston, Massachusetts 02110 [_] Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer. Check the appropriate boxes below to designate any transactions to which the statement relates: [X] third-party tender offer subject to Rule 14d-1. [ ] issuer tender offer subject to Rule 13e-4. [X] going-private transaction subject to Rule 13e-3. [_] amendment to Schedule 13D under Rule 13d-2. Check the following box if the filing is a final amendment reporting the results of the tender offer: [_] This Amendment No. 1 to Schedule TO-T/13E-3 amends and supplements the Schedule TO-T/13E-3 originally filed by National Grid Group plc ("National Grid") on March 22, 2002. This Amendment No. 1 to Schedule TO-T/13E-3 relates to the tender offers by Niagara Mohawk to purchase all of its outstanding shares of the following series of cumulative preferred stock (the "Preferred Stock") at the following applicable cash purchase prices per share: PURCHASE PRICE SERIES CUSIP NO. PER SHARE Fixed/Adjustable Rate Cumulative Preferred Stock, Series D 653522771 $53.76 Cumulative Preferred Stock, 3.40% Series 653522201 $63.43 Cumulative Preferred Stock, 3.60% Series 653522300 $67.16 Cumulative Preferred Stock, 3.90% Series 653522409 $72.76 Cumulative Preferred Stock, 4.10% Series 653522508 $76.49 Cumulative Preferred Stock, 4.85% Series 653522607 $90.49 Cumulative Preferred Stock, 5.25% Series 653522706 $93.58 -2- The offers are subject to the terms and conditions set forth in the Offer to Purchase dated February 27, 2002 (the "Offer to Purchase") and in the related Letters of Transmittal (the "Letters of Transmittal"), as amended or supplemented from time to time. Except as amended and supplemented hereby the Schedule TO-T/13E-3 filed by National Grid on March 22, 2002 remains in effect. The Schedule TO-T/13E-3 is hereby amended and supplemented as follows: ITEM 13. INFORMATION REQUIRED BY SCHEDULE 13E-3. SCHEDULE 13E-3, ITEM 8. FAIRNESS OF THE TRANSACTION. Section 6 of the Offer to Purchase ("Special Factors") is hereby amended by adding the following sentence to the end of the last paragraph under the heading "Fairness of the Offers": "The committee adopts the analysis of the Niagara Mohawk board of directors as to both the substantive and procedural fairness of the offers." -3- SIGNATURE After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Date: March 26, 2002 E NATIONAL GRID GROUP PLC BY: /s/ Richard P. Sergel ------------------------------------ Name: Richard P. Sergel Title: Group Director, North America