Exhibit 4.30-b

                  EXTENSION AND AMENDMENT AGREEMENT AND CONSENT



     This extension and amendment  agreement and consent (this  "Amendment")  is
made as of November 20, 2002, between National Westminster Bank Plc (the "Bank")
and Keyspan Generation LLC (the "Company"),  with respect to that certain letter
of credit  issued by the Bank in  connection  with those  certain New York State
Energy  Research and Development  Authority  Electric  Facilities  Revenue Bonds
(KeySpan Generation  Project) 1997 Series A (KeySpan  Generation  Projects) (the
"Letter of Credit"),  pursuant to a Letter of Credit and Reimbursement Agreement
dated as of December 1, 2000 (as amended,  the "Agreement") between the Bank and
the Company.  Capitalized terms used herein and not otherwise defined shall have
the meaning given to them in the Agreement.

     1. Pursuant to Section 2.1 (b) of the Agreement,  the Company has requested
a waiver of the notice provisions with respect to the extension of the Letter of
Credit and also requested an extension of the Stated  Termination Date as of the
date  hereof  from Dec 11, 2002 to Dec 11,  2003,  and the Bank,  subject to the
execution of this Amendment and satisfaction of the terms and conditions hereof,
is willing to so extend the Stated  Termination Date pursuant to an amendment of
the Letter of Credit in the form of Exhibit "A" hereto.

     2. In  connection  with such request the Company  agrees to pay to the Bank
all fees and expenses as set forth in Section 2.6 of the  Agreement,  and to pay
to the Bank on the  date  hereof  a  renewal  fee of  $13,528.00  and  allocated
internal costs of $1,500.00.

3. The Agreement is amended as follows:

a.   Section 1.1 of the Agreement is amended by deleting the  following  defined
     terms therein and their respective definitions:

     "ABR Loans,  Applicable Margin,  Board,  Borrowing,  Borrowing  Conditions,
     Borrowing Date,  Eurocurrency  Reserve  Requirement,  Eurodollar Base Rate,
     Eurodollar  Loans,  Eurodollar Rate, Final Maturity Date,  Interest Payment
     Date, Interest Period, Loans, and Type";

     and by amending the following definitions by amending and restating them in
     their entirety as follows:

     ""Business Day" shall mean a day other than a Saturday, Sunday or other day
     on which  commercial  banks in New York City are  authorized or required by
     law to close."

     "Obligations"  shall mean all obligations and liabilities of the Company to
     the Bank,  whether direct or indirect,  absolute or  contingent,  due or to
     become due, or now existing or hereafter  incurred,  which may arise under,
     out of, or in connection  with,  this Agreement or any other document made,
     delivered or given in connection herewith or therewith,  whether on account
     of  principal,  interest,  reimbursement  obligations,  fees,  indemnities,
     costs,  expenses  (including all fees, charges and disbursements of counsel
     to the Bank that are required to be paid by the Company pursuant hereto) or
     otherwise."

b.   Section 2.2 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section 2.2 Agreement to Reimburse the Bank for Letter of Credit Payments.


     (a)  Reimbursement  by Company.  The Company hereby agrees to reimburse and
     pay to the Bank,  on the date each payment or  disbursement  is made by the
     Bank under the Letter of Credit honoring any demand for payment made by the

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     Trustee  thereunder  (including  amounts in respect of the reinstatement of
     the Interest Component (as defined in the Letter or Credit) at the election
     of the Bank  notwithstanding  any failure of the Company to  reimburse  the
     Bank for any  previous  drawing to pay  interest on the  Bonds),  an amount
     equal to such payment or disbursement.  Any amount not so paid on such date
     shall  bear  interest,  payable  on  demand,  in  accordance  with  Section
     2.5(c)(ii).

     (b)  Reimbursement  Obligation  Absolute and  Unconditional.  The Company's
     obligation  to reimburse  the Bank when due for payments and  disbursements
     made by the  Bank  under  the  Letter  of  Credit  shall  be  absolute  and
     unconditional  under  any and all  circumstances  and  irrespective  of any
     setoff,  counterclaim  or defense to payment  that the  Company may have or
     have had against the Bank, including,  without limitation, any counterclaim
     or defense  which is based upon (i) the  failure of such demand for payment
     to conform to the terms of the  Letter of Credit,  (ii) any  failure of the
     Issuer or the  Company to receive  all or any part of the  proceeds  of the
     sale of the  Bonds,  (iii) any  non-application  or  misapplication  by the
     Issuer,  the Trustee or any other person of the proceeds of such demand for
     payment   or   (iv)   the   illegality,    invalidity,    irregularity   or
     unenforceability of the Bonds or the Letter of Credit;  provided,  however,
     that (A) the Company  shall not be obligated to reimburse  the Bank for any
     wrongful  payment  or  disbursement  made by the Bank  under the  Letter of
     Credit as a result of acts or omissions constituting intentional or willful
     misconduct  on the part of the Bank or any of its  officers,  employees  or
     agents,  and (B) except as specifically  provided herein,  the Company does
     not waive any legal rights to which it is entitled."

c.   Section 2.3 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section 2.3 Intentionally Deleted."

d.   Section 2.4 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section  2.4  Change of  Control.(a)  Upon the  occurrence  of a Change of
     Control,  whether  arising  through  the  exercise  of the LIPA  Option  or
     otherwise,  the Company shall immediately use its best efforts to cause the
     Letter of Credit to be  terminated  and  returned  to the Bank,  or failing
     that, the Company shall  immediately  deposit with, and under the exclusive
     dominion  and  control  of, the Bank cash of an amount  equal to the Stated
     Amount  of the  Letter  of  Credit  as cash  collateral  for the  Company's
     contingent  obligation to reimburse the Bank for any subsequent amount paid
     or disbursed by the Bank under the Letter of Credit.  For the  avoidance of
     doubt,  the  foregoing  obligation  to  cash  collateralize  the  Company's
     reimbursement  obligation shall not affect such reimbursement  obligations,
     which shall remain in full force and effect.  The Company agrees to execute
     such  documents  and take all such other steps as the Bank shall require to
     create and perfect a security  interest in such cash collateral in favor of
     the Bank for such purposes."

e.   Section 2.5 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section  2.5  Interest.(b)  If all or a portion of any fee or other amount
     payable  hereunder  including  any amount to be  reimbursed  under  Section
     2.2(a)  shall not be paid when due  (whether  at the  stated  maturity,  by
     acceleration  or  otherwise),  such  overdue  amount  shall bear  interest,
     payable  on demand,  at a rate per annum  equal to the ABR plus 2%, in each
     case from the date due until paid in full."

f.   Section 2.6 of the Agreement is amended by deleting subpart (d) thereof.


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<PAGE>



g.   Section 2.7 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section  2.7  Computation  of  Interest  and  Fees.  (c) (a) Fees  payable
     pursuant  hereto shall be calculated on the basis of a 360-day year for the
     actual days elapsed,  and interest payable hereunder shall be calculated on
     the basis of a 365- (or 366-,  as the case may be) day year for the  actual
     days elapsed.  Any change in the interest rate  resulting  from a change in
     the ABR shall become  effective as of the opening of business on the day on
     which such change becomes effective.  The Bank shall as soon as practicable
     notify the Company of the effective date and the amount of each such change
     in  interest  rate.  Each  determination  of an  interest  rate by the Bank
     pursuant to any provision of this Agreement shall be conclusive and binding
     on the Company in the absence of manifest error."

h.   Section 2.8 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section 2.8 Intentionally Deleted."


i.   Section 2.9 of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section 2.9 Payments.  (d) (a) All payments (including  prepayments) to be
     made by the Company hereunder,  whether on account of principal,  interest,
     fees or otherwise,  shall be made without setoff or counterclaim  and shall
     be made prior to 12:00 Noon, New York City time, on the due date thereof to
     the Bank,  at the office  specified in Section 8.2 (and such account as the
     Bank shall have  notified to the Company) (or as otherwise  notified to the
     Company by the Bank), in Dollars and in immediately available funds. If any
     payment  hereunder  becomes  due and payable on a day other than a Business
     Day, such payment shall be extended to the next succeeding Business Day. In
     the case of any  extension  of any  payment of  principal  pursuant  to the
     preceding  sentence,  interest  thereon shall be payable at the  applicable
     rate during such extension."

j.   Section 2.10 of the  Agreement  is amended by amending and  restating it in
     its entirety as follows:


     "Section 2.10  Requirements  of Law. (a) If the Bank shall have  determined
     that the  adoption  of or any change in any  Requirement  of Law  regarding
     capital  adequacy  or in  the  interpretation  or  application  thereof  or
     compliance  by the Bank or any  corporation  controlling  the Bank with any
     request or directive  regarding capital adequacy (whether or not having the
     force of law) from any  Governmental  Authority made subsequent to the date
     of this  Agreement  shall have the effect of reducing the rate of return on
     the  Bank's  or  such  corporation's   capital  as  a  consequence  of  its
     obligations  hereunder  to a  level  below  that  which  the  Bank  or such
     corporation could have achieved but for such adoption, change or compliance
     (taking into consideration the Bank's or such  corporation's  policies with
     respect  to  capital  adequacy)  by an  amount  deemed  by the  Bank  to be
     material,  then  from  time to time,  after  submission  by the Bank to the
     Company of a written  request  therefor,  the Company shall pay to the Bank
     such  additional  amount or  amounts as will  compensate  the Bank for such
     reduction;  provided  that the Company  shall not be required to compensate
     the Bank pursuant to this paragraph for any amounts  incurred more than six
     months  prior to the date that the Bank  notifies the Company of the Bank's
     intention to claim compensation therefor; and provided further that, if the
     circumstances  giving rise to such claim have a  retroactive  effect,  then
     such  six-month  period  shall be  extended  to include  the period of such
     retroactive effect.


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<PAGE>


          (b) A certificate as to any  additional  amounts  payable  pursuant to
     this Section  submitted by the Bank to the Company  shall be  conclusive in
     the absence of manifest error.  The obligations of the Company  pursuant to
     this  Section  shall  survive the  termination  of this  Agreement  and the
     payment of amounts payable hereunder."

(k)  Section 2.12 and Section 2.13 are deleted in their entirety.

(l)  Section  6.1(a)of the  Agreement is amended by amending and restating it in
     its entirety as follows:

     "(a) (i) the Company  shall fail to pay to make any  reimbursement  payment
     under Section 2.2(a) when due in accordance therewith;  or (ii) the Company
     shall fail to pay any other amount payable hereunder within five days after
     such  other  amount  becomes  due in  accordance  with  the  terms  of this
     Agreement; or"

(m)  Section  6.2of the Agreement is amended by amending and restating it in its
     entirety as follows:

     "Section  6.2  Remedies  Upon an Event of Default.  If any Event of Default
     shall have occurred and be continuing,  the Bank may (i) notify the Trustee
     of the  occurrence and  continuance of such Event of Default  whereupon the
     Trustee  shall  accelerate  payment  of all the  outstanding  Bonds and the
     interest  accrued thereon  pursuant to and in accordance with Section 10.01
     of the  Indenture,  and notify the Trustee of the Bank's  determination  to
     terminate  the  Letter of Credit on the 12th  Business  Day  following  the
     Trustee's  receipt of such notice,  and, in either case,  provide a copy of
     such  notice  to the  Company  and the  Issuer,  (ii) if a  drawing  to pay
     interest  on the Bonds  shall  have been  made  under the  Letter of Credit
     (other  than such a drawing  in respect of the  payment  of  interest  upon
     scheduled or accelerated maturity, or redemption, of the Bonds), notify the
     Trustee prior to the tenth day following such drawing that the Bank has not
     been  reimbursed  for such  drawing  and that the  Interest  Component  (as
     defined in the Letter of Credit) in the amount of such  drawing will not be
     reinstated, (iii) require the Company to provide cash collateral in respect
     of the  undrawn  portion  of the  Stated  Amount of the  Letter of  Credit,
     whereupon  the Company  shall  deposit with the Bank as cash  collateral an
     amount  equal to such  undrawn  portion,  (v)  exercise  all the rights and
     remedies provided herein; provided, however, that in the event of an actual
     or deemed  entry of an order for relief with  respect to the Company or any
     of  its  Subsidiaries  under  the  Federal  Bankruptcy  Code,  all  amounts
     reimbursable  pursuant to Section 2.02(a),  all interest accrued and unpaid
     thereon and all other amounts payable hereunder shall automatically  become
     due and payable, without presentment,  demand, protest or any notice of any
     kind, all of which are hereby expressly waived by the Company."

(n)  Section 7.3 is deleted in its entirety.

4.   The Company reaffirms each of the representations and warranties  contained
     in the  Agreement  as of the date  hereof as though made on the date hereof
     and reaffirms each of its obligations under the Agreement.

          In  witness  whereof,  the  Company  and the Bank have  executed  this
     Amendment  in  counterpart  copies (all of which shall  constitute  but one
     original) as of the date set forth above.


                                           KEYSPAN GENERATION LLC



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


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<PAGE>


                                           NATIONAL WESTMINSTER BANK PLC
                                           NEW YORK BRANCH



                                           By:    /s/
                                           --------------------------
                                           Name:  Patricia J. Dundee
                                           Title: Senior Vice President




















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<PAGE>



                                   EXHIBIT "A"



AMENDMENT TO LETTER OF CREDIT

IRREVOCABLE LETTER OF CREDIT
NO. NWB2030

November 27, 2002


The Chase Manhattan Bank
450 W. 33rd Street - 15th Floor
New York, NY 10001


                     ATTENTION: CAPITAL MARKETS FIDUCIARY SERVICES

Dear Sir or Madam:

At the request of Keyspan Generation LLC, we hereby amend our Irrevocable Letter
of Credit No.  NWB2030 by deleting the Stated  Termination  Date of December 11,
2002 set forth therein and replacing it with December 11, 2003.

Please  acknowledge  your receipt of and consent to this  amendment by executing
the enclosed  copy of this  amendment and returning it to Ms. Sheila Shaw at the
address set forth above.


Very truly yours,


NATIONAL WESTMINSTER BANK PLC, NEW YORK BRANCH



By: /s/
-------------------
Authorized Officer



By: /s/
-------------------
Authorized Officer




Acknowledged and consented to on November __, 2002:

The Chase Manhattan Bank


By: /s/
--------------------
Name:
Title: