Exhibit 23-a            Consent of Arthur Andersen, LLP, Independent Accountants


                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS



As independent  public  accountants,  we hereby consent to the  incorporation by
reference in this  registration  statement  (Registration  No. 333-43768) of our
report dated  January 27, 2000 included in KeySpan  Corporation's  Form 10-K for
the year ended December 31, 1999. We also hereby consent to the incorporation by
reference in the  registration  statement of our report dated  January 21, 2000,
appearing in the Annual Report on Form 10-K of Eastern  Enterprises for the year
ended December 31, 1999.





/s/ARTHUR ANDERSEN LLP



New York, New York
October 13, 2000












Exhibit 23-b            Consent of Ernst & Young LLP


                        CONSENT OF INDEPENDENT AUDITORS

We  consent to the  reference  to our firm under the  caption  "Experts"  in the
Registration  Statement,  as amended,  (Form S-3 Registration No. 333-43768) and
the  related   Prospectus  of  KeySpan   Corporation  for  the  registration  of
$1,650,000,000  of debt securities and to the incorporation by reference therein
of our report dated May 22, 1998,  with respect to the financial  statements and
schedule of Long Island  Lighting  Company  included in the Annual  Report (Form
10-K),  as  amended,  of  KeySpan  Corporation  (formerly  known  as  MarketSpan
Corporation) for the transition  period from April 1, 1998 to December 31, 1998,
filed with the Securities and Exchange Commission.


/s/ERNST & YOUNG LLP



Melville, New York
October 13, 2000