Exhibit 4.9

                             DECLARATION OF TRUST


          DECLARATION OF TRUST, dated as of May 3, 2001, between
KeySpan Corporation, a New York corporation, as Sponsor, Chase Manhattan Bank
USA, National Association, as the initial Delaware Trustee, The Chase
Manhattan Bank, as the initial Property Trustee, and Ronald S. Jendras,
Richard A. Rapp, and Michael J. Taunton, as Regular Trustees (collectively with
the Delaware Trustee and the Property Trustee, the "Trustees"). The Sponsor and
the Trustees hereby agree as follows:

          1. The trust created hereby (the "Trust") shall be known as "KeySpan
Trust III", in which name the Trustees, or the Sponsor to the extent provided
herein, may conduct the business of the Trust, make and execute contracts, and
sue and be sued.

          2. The Sponsor hereby assigns, transfers, conveys and sets over to
the Trustees the sum of Ten Dollars ($10.00). The Trustees hereby acknowledge
receipt of such amount in trust from the Sponsor, which amount shall
constitute the initial trust estate. The Trustees hereby declare that they
will hold the trust estate in trust for the Sponsor. It is the intention of
the parties hereto that the Trust created hereby constitute a business trust
under Chapter 38 of Title 12 of the Delaware Code, 12 Del C. Section 3801 et
seq. (the "Business Trust Act"), and that this document constitute the
governing instrument of the Trust. The Trustees are hereby authorized and
directed to execute and file a certificate of trust with the Delaware
Secretary of State in the form attached hereto.

          3. The Sponsor and the Trustees will enter into an amended and
restated Declaration of Trust, satisfactory to each such party (and
substantially in the form included as an exhibit to the 1933 Act Registration
Statement (as defined below)), to provide for the contemplated operation of
the Trust created hereby and the issuance of preferred securities (the
"Preferred Securities") and common securities by the Trust as such securities
will be described therein. Prior to the execution and delivery of such amended
and restated Declaration of Trust, the Trustees shall not have any duty or
obligation hereunder or with respect to the trust estate, except as otherwise
required by applicable law or as may be necessary to obtain prior to such
execution and delivery and licenses, consents or approvals required by
applicable law or otherwise.



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          4. The Sponsor and the Trustees hereby authorize and direct the
Sponsor, in each case on behalf of the Trust as agent of the Trust, (i) to
prepare for filing with the Securities and Exchange Commission (the
"Commission") (a) a Registration Statement on Form S-3 (the "1933 Act
Registration Statement"), including any pre-effective or post-effective
amendments to the 1933 Act Registration Statement, relating to the registration
under the Securities Act of 1933, as amended, of the Preferred Securities of
the Trust and possibly certain other securities and (b) a Registration
Statement on Form 8-A (the "1934 Act Registration Statement") (including all
pre-effective and post-effective amendments thereto) relating to the
registration of the Preferred Securities of the Trust under the Securities
Exchange Act of 1934, as amended; (ii) to prepare and file with the New York
Stock Exchange or any other national stock exchange or The Nasdaq National
Market (each, an "Exchange") and execute on behalf of the Trust one or more
listing applications and all other applications, statements, certificates,
agreements and other instruments as shall be necessary or desirable to cause
the Preferred Securities to be listed on any of the Exchanges; (iii) to
negotiate and execute an underwriting agreement among the Trust, the Sponsor
and the underwriter(s) party thereto relating to the offer and sale of the
Preferred Securities, substantially in the form included or to be incorporated
as an exhibit to the 1933 Act Registration Statement and (iv) to prepare,
execute and file such applications, reports, surety bonds, irrevocable
consents, appointments of attorneys for service of process and other papers
and documents as shall be necessary or desirable to register the Preferred
Securities under the securities or "Blue Sky" laws of such jurisdictions as
the Sponsor, on behalf of the Trust, may deem necessary or desirable.

          It is hereby acknowledged and agreed that in connection with
any document referred to in clauses (i), (ii) and (iv) above, (A) any Regular
Trustee (or his attorneys-in-fact and agents or the Sponsor as permitted
herein) is authorized to execute such document on behalf of the Trust,
provided that the 1933 Act Registration Statement and the 1934 Act
Registration Statement shall be signed by all of the Regular Trustees, and (B)
The Chase Manhattan Bank and Chase Manhattan Bank USA, National Association,
in their capacities as Trustees of the Trust, shall not be required to join in
any such filing or execute on behalf of the Trust any such document unless
required by the rules and regulations of the Commission, the Exchanges or
state securities or blue sky laws, and in such case only to the extent so
required. In connection with all of the foregoing, each Regular Trustee,
solely in such Regular Trustee's capacity as Trustee of the Trust, hereby
constitutes and appoints Ronald S. Jendras, Richard A. Rapp, Jr. and
Michael J. Taunton and each of them, as such Regular Trustee's true and lawful
attorneys-in-fact and agent, with full power of substitution and
resubstitution, for such Regular Trustee, in such Regular Trustee's name, place
and stead, in any and all capacities, to sign any and all amendments (including
post-effective amendments) to the 1933 Act Registration Statement and the 1934
Act Registration Statement and to file the same, with all exhibits thereto, and
other documents in connection therewith, with the Commission, the Exchanges and
administrators of state securities or blue sky laws, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each
and every act and thing requisite and necessary to be done in connection
therewith, as fully to all intents and purposes as such Regular Trustee might
or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their respective substitute or
substitutes, shall do or cause to be done by virtue hereof.

          5.  This Declaration of Trust may be executed in one or more
counterparts.

          6. The number of Trustees initially shall be five (5) and thereafter
the number of Trustees shall be such number as shall be fixed from time to time
by a written instrument signed by the Sponsor which may increase or decrease
the number of Trustees; provided that, to the extent required by the Business
Trust Act, one Trustee shall be an entity that has its principal place of
business in the State of Delaware. Subject to the foregoing, the Sponsor is
entitled to appoint or remove without cause any Trustee at any time. The
Trustees may resign upon thirty days prior notice to the Sponsor.


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          IN WITNESS WHEREOF, the parties hereto have caused this
Declaration of Trust to be duly executed as of the day and year first above
written.



                                   KEYSPAN CORPORATION,
                                   as Sponsor


                                   By: /s/ Gerald Luterman
                                       ___________________________________
                                       Name:  Gerald Luterman
                                       Title: Senior Vice President and
                                                Chief Financial Officer


                                   CHASE MANHATTAN BANK USA,
                                   NATIONAL ASSOCIATION,
                                   as Delaware Trustee


                                   By: /s/ Denis Kelly
                                       ____________________________________
                                       Name:  Denis Kelly
                                       Title:  Assistant Vice President


                                   THE CHASE MANHATTAN BANK,
                                   as Property Trustee


                                   By: /s/ Francine Springer
                                       ____________________________________
                                       Name:   Francine Springer
                                       Title:  Assistant Vice President



                                       /s/ Ronald S. Jendras
                                       ___________________________________
                                       Name:  Ronald S. Jendras
                                       Title: Regular Trustee



                                       /s/ Richard A. Rapp, Jr.
                                       ___________________________________
                                       Name:  Richard A. Rapp, Jr.
                                       Title: Regular Trustee



                                       /s/ Michael J. Taunton
                                       ___________________________________
                                       Name:  Michael J. Taunton
                                       Title: Regular Trustee