Exhibit 32.1



                              CERTIFICATION OF THE

                      CHAIRMAN AND CHIEF EXECUTIVE OFFICER

                             PURSUANT TO SECTION 906

                        OF THE SARBANES-OXLEY ACT OF 2002


     In  connection  with the Report on Form 10-Q for the period  ended June 30,
2006 of KeySpan  Corporation (the  "Corporation"),  as filed with the Securities
and Exchange Commission on the date hereof (the "Report"),  I, Robert B. Catell,
Chairman and Chief Executive Officer of the Corporation, certify, pursuant to 18
U.S.C.  Section 1350, as adopted  pursuant to Section 906 of the  Sarbanes-Oxley
Act of 2002, that:

(1)  The Report fully complies with the  requirements  of Section 13(a) or 15(d)
     of the Securities Exchange Act of 1934, as amended; and

(2)  The information  contained in the Report fairly  presents,  in all material
     respects, the financial condition and results of operations of the Company.


Date:     August 3, 2006


                                              /s/Robert B. Catell
                                              --------------------------
                                              Robert B. Catell
                                              Chairman of the Board of Directors
                                              and Chief Executive Officer