UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549


                                    FORM 8-K


                             Current Report Pursuant
                          to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934



       Date of report (Date of earliest event reported): December 13, 2006


                               KEYSPAN CORPORATION
             (Exact Name of Registrant as Specified in Its Charter)


                                    New York
                 (State or Other Jurisdiction of Incorporation)


        1-14161                                         11-3431358
(Commission File Number)                      (IRS Employer Identification No.)

              175 East Old Country Road, Hicksville, New York 11801
                 One MetroTech Center, Brooklyn, New York 11201
               (Address of Principal Executive Offices) (Zip Code)

                           (516) 755-6650 (Hicksville)
                            (718) 403-1000 (Brooklyn)
              (Registrant's Telephone Number, Including Area Code)



                                      N/A
          (Former Name or Former Address, if Changed Since Last Report)












Check  the  appropriate  box  below  if the  Form  8-K  filing  is  intended  to
simultaneously  satisfy the filing obligation of the registrant under any of the
following provisions:

[ ]  Written  communications  pursuant to Rule 425 under the  Securities Act (17
     CFR 230.425)

[ ]  Soliciting  material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
     240.14a-12)

[ ]  Pre-commencement   communications  pursuant  to  Rule  14d-2(b)  under  the
     Exchange Act (17 CFR 240.14d-2(b))

[ ]  Pre-commencement   communications  pursuant  to  Rule  13e-4(c)  under  the
     Exchange Act (17 CFR 240.13.e-4(c))










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Cautionary Language Concerning Forward-Looking Statements
- ---------------------------------------------------------

     Certain statements contained herein are "forward-looking statements" within
the meaning of Section 21E of the  Securities  Exchange Act of 1934, as amended,
which reflect  numerous  assumptions and estimates and involve a number of risks
and  uncertainties.  For these  statements,  we claim the protection of the safe
harbor  for  forward-looking  statements  provided  by  the  Private  Securities
Litigation Reform Act of 1995.

     There are  possible  developments  that could  cause our actual  results to
differ  materially  from those  forecasted  or  implied  in the  forward-looking
statements.   You  are   cautioned   not  to  place  undue   reliance  on  these
forward-looking  statements,  which  are  current  only  as of the  date of this
filing.  We  disclaim  any  intention  or  obligation  to update  or revise  any
forward-looking  statements,  whether  as a result  of new  information,  future
events or otherwise.

     Among the factors that could cause actual results to differ materially are:
the occurrence of any event,  change or other circumstances that could give rise
to the termination of the merger  agreement with National Grid or the failure of
the merger to close for any reason; volatility of energy prices used to generate
electricity;  fluctuations  in weather and in gas and electric  prices;  general
economic  conditions,  especially in the Northeast United States; our ability to
successfully manage our cost structure and operate  efficiently;  our ability to
successfully contract for natural gas supplies required to meet the needs of our
customers;  implementation of new accounting  standards or changes in accounting
standards  or GAAP  which  may  require  adjustments  to  financial  statements;
inflationary  trends and interest rates;  the ability of KeySpan to identify and
make complementary  acquisitions,  as well as the successful integration of such
acquisitions;   available  sources  and  cost  of  fuel;   creditworthiness   of
counterparties to derivative instruments and commodity contracts; the resolution
of certain  disputes with Long Island Power Authority  ("LIPA")  concerning each
party's  rights and  obligations  under  various  agreements;  retention  of key
personnel;  federal and state  regulatory  initiatives  that  threaten  cost and
investment recovery,  and place limits on the type and manner in which we invest
in new businesses and conduct operations; the impact of federal, state and local
utility  regulatory  policies,  legislation  and  orders  on our  regulated  and
unregulated  businesses;  potential  write-down of our investment in natural gas
properties  when  natural  gas prices are  depressed  or if we have  significant
downward revisions in our estimated proved gas reserves;  competition facing our
unregulated  Energy  Services  businesses;   the  degree  to  which  we  develop
unregulated  business ventures,  as well as federal,  state and local regulatory
policies  affecting  our ability to retain and operate  such  business  ventures
profitably;  a change in the fair value of our  investments  that could  cause a
significant  change in the carrying  value of such  investments  or the carrying
value of related  goodwill;  timely  receipts of  payments  from our two largest
customers LIPA and the New York Independent  System Operator changes in the UCAP
pricing structure; timing of the approval of the 2006 LIPA Agreements and; other
risks detailed from time to time in other reports and other  documents  filed by
KeySpan with the Securities and Exchange Commission.


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Item 1.01      Entry into a Material Definitive Agreement

On February 7, 2006, KeySpan Corporation ("KeySpan") filed a Form 8-K under Item
1.01 - Entry  into a  Material  Definitive  Agreement  disclosing,  among  other
things,  the intention of KeySpan  Generation LLC, a wholly-owned  subsidiary of
KeySpan,  to enter into an Option and Purchase and Sale  Agreement  (the "Option
Agreement") with Long Island Lighting Company d/b/a LIPA ("LIPA").

The Option  Agreement  granted LIPA the option during the period January 1, 2006
to December 31, 2006 to purchase only KeySpan's Far Rockaway and/or E.F. Barrett
Generating  Stations  (and certain  related  assets) at a price equal to the net
book value of each facility.

On  December  13,  2006,  KeySpan  Generation  and  LIPA  entered  into a Letter
Amendment,  effective  as of December  11, 2006,  to the Option  Agreement  (the
"Amendment"),  whereby the parties have agreed to extend the expiration  date of
the Option  Agreement.  Pursuant to the  Amendment,  the Option  Agreement  will
expire  at 3:00  p.m.  on the  later of (a)  December  31,  2007 or (b) 180 days
following the effective date of the Option Agreement.

The  effectiveness  of the Option  Agreement,  the  Amendment  and other related
agreements remain contingent upon receipt of certain regulatory approvals.

This  description of the Option  Agreement and the Amendment are subject to, and
qualified in their entirety by, reference to the Option  Agreement,  filed as an
Exhibit to the  February 7, 2006 Form 8-K,  and  Amendment,  attached  hereto as
Exhibit 10.1.


Item 9.01.     Financial Statements and Exhibits.

               Exhibits.

               10.1 Letter  Amendment  to  the  Option  and  Purchase  and  Sale
                    Agreement  between  KeySpan  Generation  LLC and Long Island
                    Lighting Company d/b/a LIPA, dated as of December 11, 2006













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                                    SIGNATURE


     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.



                                              KEYSPAN CORPORATION

Dated: December 19, 2006                  By: /s/ Gerald Luterman
                                              -------------------
                                              Name:  Gerald Luterman
                                              Title: Executive Vice President
                                                     and Chief Financial Officer











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