EXHIBIT 99.1




                    CERTIFICATION PURSUANT TO
                     18 U.S.C SECTION 1350,
                     AS ADOPTED PURSUANT TO
          SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


                            
The undersigned hereby certifies, in my capacity as an officer
of NSTAR, for purposes of 18 U.S.C. Section 1350, as adopted
pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that
to the best of my knowledge:

  (i)  the enclosed Annual Report of NSTAR on Form 10-K for the
       year ended December 31, 2002 fully complies with the
       requirements of Section 13(a) or 15(d) of the Securities
       Exchange Act of 1934; and

  (ii) the information contained in such Report fairly presents,
       in all material respects, the financial condition and
       results of operations of NSTAR.

Dated:  March 27, 2003           By:    /s/ THOMAS J. MAY
                                        Thomas J. May
                                        Chairman, President and
                                        Chief Executive Officer