KEYSPAN CORPORATION
                              One MetroTech Center
                          Brooklyn, New York 11201-3850

                                 (718) 403-1000
                       ----------------------------------




July 19, 2006

VIA EDGAR TRANSMISSION
- ----------------------

Securities and Exchange Commission
Division of Corporation Finance
100 F Street, N.E.
Washington, D.C. 20549
Attn:  Jim Allegretto, Senior Assistant Chief Accountant


         Re:      KeySpan Corporation
                  Form 10-K for Fiscal Year Ended December 31, 2005
                  File No. 1-14161

Dear Mr. Allegretto:

     KeySpan  Corporation  (the  "Company") sets forth below its response to the
comments of the staff of the Division of  Corporation  Finance (the  "Staff") of
the  Securities  and Exchange  Commission  (the  "Commission")  contained in the
letter  received by telecopy on June 29,  2006 (the  "Second  Comment  Letter"),
concerning  the KeySpan  Form 10-K for the fiscal year ended  December 31, 2005.
For your convenience,  we have set forth the text of the comment from the Second
Comment Letter, followed by the response.

     1.   We note your  response  to comment  five of our  letter  dated June 1,
          2006.  While we concur that the initial June 2004 Houston  Exploration
          Company transaction was not a significant disposition, we believe that
          a  significant  disposition  occurred  when  you sold  your  remaining
          interest  irrespective  of whether it was  contemplated.  Please amend
          your Form 8-K filed on  November  19,  2004 to  include  the pro forma
          financial statements required by Article 11 of Regulation S-X.

     KeySpan viewed the June 2004 and November 2004 transactions as separate and
distinct and not part of a single plan to sell all or any  specified  portion of
our  investment in Houston  Exploration.  Each  transaction  was evaluated on an
isolated  basis and involved very distinct terms and  structures,  in each case,




Securities and Exchange Commission
Division of Corporation Finance
July 19, 2006
Page 2


driven by unrelated and  unanticipated  external  factors,  including a dramatic
increase in the market price of Houston  Exploration's  common stock in November
2004.  At the time of the June 2004  transaction,  KeySpan had no intent to sell
its remaining 23.5% ownership interest in Houston  Exploration and elected to do
so in November 2004 solely as a result of the significant appreciation in market
price of Houston Exploration's common stock and the belief that a disposition at
such time would maximize the value of such investment for the benefit of KeySpan
shareholders.

     KeySpan  reviewed  its  investment  in  Houston  Exploration  for pro forma
disclosure  consideration  at the  time of the  November  2004  transaction  and
concluded that the sale did not meet the pro forma requirements of a disposal of
a significant subsidiary.  Specifically, based on our review and analysis of the
requirements of Article 11 of Regulation S-X as it relates to the disposition of
a business, we concluded that (i) a significant  disposition had not occurred as
of November  2004;  and (ii) we were not required to aggregate the November 2004
disposition  with the June 2004  disposition  in  connection  with this analysis
since they were separate and distinct transactions and not part of a single plan
to  dispose  of  our  investment  in  Houston   Exploration.   Accordingly,   we
respectfully  submit that pro forma  financial  statements  were not required by
Article 11 of  Regulation  S-X to be  included in our Form 8-K filed on November
19, 2004.

     Please direct any questions  concerning  this letter to the  undersigned at
(718)  403-6904 or to Alfred C. Bereche,  Associate  General  Counsel,  at (516)
545-5028.


                                                      Very truly yours,
                                                      /s/Theresa A. Balog
                                                      --------------------
                                                      Theresa A. Balog
                                                      Vice President and
                                                      Chief Accounting Officer



cc:   H. Christopher Owings, Assistant Director
      Robert Babula, Staff Accountant