FIRST AMENDMENT

     FIRST AMENDMENT, dated as of March 7, 2001 (this "First Amendment"), to the
Credit Agreement (the "Credit Agreement"), dated as of September 22, 2000, among
KEYSPAN CORPORATION, a New York corporation (the "Borrower"),  the several banks
and other  financial  institutions or entities from time to time parties thereto
(the "Lenders"),  CITIBANK,  N.A. and ABN AMRO BANK,  N.V., as  Co-Documentation
Agents,  J.P.  MORGAN  SECURITIES  INC.,  as  Syndication  Agent  and THE  CHASE
MANHATTAN BANK, as Administrative Agent.

                                                W I T N E S S E T H
                                                -------------------

                  WHEREAS, pursuant to the Credit Agreement, the Lenders have
agreed to make, and have made, certain extensions of credit to the Borrower; and

                  WHEREAS, the Borrower has requested that the Lenders amend
Section 6.1(a) of the Credit Agreement in the manner provided herein; and

                  WHEREAS, the Lenders are willing to agree to the requested
amendment, but only upon the terms and conditions set forth herein;

                    NOW THEREFORE,  in consideration  of the premises  contained
               herein, the parties hereto agree as follows:

               1. Defined Terms.  Unless otherwise  defined herein,  capitalized
          terms  which are  defined in the Credit  Agreement  are used herein as
          defined therein.

               2.  Amendment  to Section  6.1(a).  Section  6.1(a) of the Credit
          Agreement is hereby  amended by deleting  such Section in its entirety
          and substituting in lieu thereof the following:

                  "Permit the ratio of Consolidated Indebtedness to Consolidated
         Capitalization as at the last day of (i) any fiscal quarter other than
         the fiscal quarters ending December 31, 2000, March 31, 2001 and June
         30, 2001 to exceed 0.65:1.00 and (ii) fiscal quarters ending December
         31, 2000, March 31, 2001 and June 30, 2001 to exceed 0.68:1.00."

               3. Effectiveness.  This First Amendment shall become effective as
          of December 30, 2000 upon receipt by the Administrative  Agent of duly
          executed  counterparts of this First Amendment by each of the Borrower
          and the Required Lenders.

               4. Representations and Warranties.  On and as the date hereof and
          after  giving  effect to this  First  Amendment  the  Borrower  hereby
          confirms,  reaffirms and restates the  representations  and warranties
          set forth in the  Credit  Agreement  mutatis  mutandis,  except to the
          extent that such  representations and warranties expressly relate to a
          specific  earlier  date in which case the  Borrower  hereby  confirms,
          reaffirms and restates such  representations and warranties as of such
          earlier date.

               5. Continuing  Effect; No Other  Amendments.  Except as expressly
          amended  hereby,  all of  the  terms  and  provisions  of  the  Credit
          Agreement are and shall remain in full force and effect. The amendment
          provided for herein is limited to the  specific  Section of the Credit
          Agreement  specified  herein  and  narrowly  construed  and  shall not
          constitute an amendment  of, or an  indication  of the  Administrative
          Agent's or the Lenders'  willingness to amend, any other provisions of
          the Credit Agreement.

               6.  Expenses.  The  Borrower  agrees  to pay  and  reimburse  the
          Administrative  Agent  for  all  its  reasonable  costs  and  expenses
          incurred in connection with the preparation and delivery of this First
          Amendment,  including,  without  limitation,  the reasonable  fees and
          disbursements of counsel to the Administrative Agent.

               7.  Counterparts.  This First Amendment may be executed by one or
          more of the parties to this First  Amendment on any number of separate
          counterparts  (including  by telecopy),  and all of said  counterparts
          taken  together  shall  be  deemed  to  constitute  one and  the  same
          instrument.  A set of the copies of this First Amendment signed by the
          parties   hereto   shall  be   delivered   to  the  Borrower  and  the
          Administrative Agent.

               8.  GOVERNING  LAW.  THIS  FIRST  AMENDMENT  AND THE  RIGHTS  AND
          OBLIGATIONS  OF THE  PARTIES  UNDER  THIS  FIRST  AMENDMENT  SHALL  BE
          GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAW
          OF THE STATE OF NEW YORK.



<PAGE>





                  IN WITNESS WHEREOF, the parties hereto have caused this First
Amendment to be executed and delivered by their respective duly authorized
officers as of the date first above written.

                                       KEYSPAN CORPORATION

                                       By:  /s/  Michael J. Taunton
                                           -------------------------------------
                                            Name:  Michael J. Taunton
                                            Title:  Vice President and Treasurer


                                       THE CHASE MANHATTAN BANK, as
                                       Administrative Agent and as a Lender

                                       By: /s/  Charles L. Swarns, Jr.
                                          --------------------------------
                                            Name:  Charles L. Swarns, Jr.
                                            Title:  Vice President


                                       CITIBANK N.A., as a Co-Documentation
                                       Agent and as a Lender


                                       By: /s/ Gus Rigas
                                          -------------------------------
                                            Name:  Gus Rigas
                                            Title: Vice President


                                       ABN AMRO BANK, N.V., as a Co-
                                       Documentation Agent and as a Lender


                                       By: /s/ Jeffrey Dodd
                                          -------------------------------
                                            Name:  Jeffrey Dodd
                                            Title: Group Vice President


                                       By: /s/ Kevin S. McFadden
                                          -------------------------------
                                            Name:  Kevin S. McFadden
                                            Title: Group Vice President







                                       BANK OF AMERICA, N.A.


                                       By: /s/ Gretchen P. Burud
                                           ------------------------------
                                            Name:  Gretchen P. Burud
                                            Title:  Managing Director


                                       THE BANK OF NEW YORK


                                       By: /s/ John Watt
                                           ------------------------------
                                            Name:  John Watt
                                            Title: Vice President


                                       THE BANK OF NOVA SCOTIA


                                       By: /s/ Philip N. Adsetts
                                          -------------------------------
                                            Name:  Philip N. Adsetts
                                            Title: Director


                                       BANK OF TOKYO-MITSUBISHI TRUST
                                       COMPANY


                                       By: /s/ Nicholas R. Battista
                                          -------------------------------
                                            Name:  Nicholas R. Battista
                                            Title: VP and Manager


                                       BANK ONE, NA (MAIN OFFICE -CHICAGO)


                                       By: /s/ Mary Lu D. Cramer
                                           ------------------------------
                                            Name:  Mary Lu D. Cramer
                                            Title:  Vice President







                                       BAYERISCHE LANDESBANK GIROZENTRALE,CAYMAN
                                       ISLANDS BRANCH


                                       By: /s/ Hereward Drummond
                                           -----------------------------
                                            Name:  Hereward Drummond
                                            Title: Senior Vice President


                                       By: /s/ Sean O'Sullivan
                                           -----------------------------
                                            Name:  Sean O' Sullivan
                                            Title: Vice President

                                       BARCLAYS BANK PLC


                                       By: /s/ Sydney G. Dennis
                                           ------------------------------
                                            Name:  Sydney G. Dennis
                                            Title: Director


                                       CREDIT LYONNAIS NEW YORK BRANCH


                                       By: /s/ Philippe Soustra
                                           ------------------------------
                                            Name:  Philippe Soustra
                                            Title: Senior Vice President


                                       THE DAI-ICHI KANGYO BANK, LTD.


                                       By: /s/  Andreas Panteli
                                          -------------------------------
                                            Name:  Andreas Panteli
                                            Title: Sr. Vice President


                                       EUROPEAN AMERICAN BANK


                                       By: /s/ Thomas M. Shinnick
                                          -----------------------
                                            Name:  Thomas M. Shinnick
                                            Title: Vice President


                                       FIFTH THIRD BANK


                                       By: /s/ Ann Pierson
                                           -------------------------------
                                            Name:  Ann Pierson
                                            Title: Corporate Banking Officer


                                       FLEET NATIONAL BANK


                                       By: /s/ Robert D. Lanigan
                                          --------------------------------
                                            Name:  Robert D. Lanigan
                                            Title: Managing Director


                                       THE INDUSTRIAL BANK OF JAPAN, LIMITED


                                       By: /s/ John Dippo
                                           -------------------------------------
                                            Name:  John Dippo
                                            Title: Senior Vice President


                                       MELLON BANK, N.A.


                                       By:  /s/ Richard A. Matthews
                                          -------------------------------------
                                            Name:  Richard A. Matthews
                                            Title: Vice President


                                       PNC BANK, NATIONAL ASSOCIATION


                                       By: /s/ Brian M. Begg
                                           ---------------------------------
                                            Name:  Brian M. Begg
                                            Title: Vice President


                                       ROYAL BANK OF CANADA


                                       By:  /s/ Jason York
                                          ------------------------------------
                                            Name:  Jason York
                                            Title: Manager
                                       THE ROYAL BANK OF SCOTLAND PLC


                                       By: /s/ Lee Morse
                                           -----------------------------------
                                            Name:  Lee Morse
                                            Title:  Vice President
                                       UNION BANK OF CALIFORNIA, N.A.


                                       By: /s/ Dennis G. Blank
                                           -----------------------------
                                            Name:  Dennis G. Blank
                                            Title: Vice President


                                       WESTDEUTSCHE LANDESBANK GIROZENTRALE,
                                       NEW YORK BRANCH


                                       By: /s/ Duncan M. Robertson
                                           ----------------------------
                                            Name:  Duncan M. Robertson
                                               Title: Director

                                       By: /s/ Duncan M. Robertson
                                           ----------------------------------
                                            Name:  Anthony Alessandro
                                            Title: Manager