As Filed with the Securities and Exchange Commission on April 12, 2001
                                                      Registration No. 333-53657
- --------------------------------------------------------------------------------


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                   ------------------------------------------


                        POST-EFFECTIVE AMENDMENT NO. 2 TO
                                    FORM S-3
                             REGISTRATION STATEMENT
                                      under
                           THE SECURITIES ACT OF 1933

                   ------------------------------------------


                               KEYSPAN CORPORATION
             (Exact name of registrant as specified in its charter)


                                    New York
                            (State of incorporation)
                                   11-3431358
                     (I.R.S. employer identification number)



                            Steven L. Zelkowitz, Esq.
                 One MetroTech Center, Brooklyn, New York 11201
              175 East Old Country Road, Hicksville, New York 11801
                            (718) 403-1000 (Brooklyn)

                           (516) 755-6650 (Hicksville)
                   (Address, including zip code, and telephone
                  number, including area code, of registrant's
                    principal executive offices and agent for
                                    service)


Approximate  date of commencement of proposed sale to public:  From time to time
after this  Registration  Statement  becomes  effective as  determined by market
conditions.

                        ---------------------------------


If the only securities  being registered on this form are being offered pursuant
to dividend or interest reinvestment plans, please check the following box.___

       If any of the securities  being registered on this form are to be offered
on a delayed or continuous  basis  pursuant to Rule 415 under the Securities Act
of 1933,  other than  securities  offered only in  connection  with  dividend or
interest reinvestment plans, check the following box. X
                                                     ---

       If this form is filed to register  additional  securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number






of the earlier effective registration statement for the same offering. ___

       If this form is a post-effective  amendment filed pursuant to Rule 462(c)
under the  Securities  Act,  check the following box and list the Securities Act
registration  statement number of the earlier effective  registration  statement
for the same offering. ___

       If delivery  of the  prospectus  is expected to be made  pursuant to Rule
434, please check the following box. ___

       The Registrants hereby amend this Registration  Statement on such date or
dates as may be  necessary  to delay its  effective  date until the  Registrants
shall file a further amendment which specifically  states that this Registration
Statement shall  thereafter  become effective in accordance with Section 8(a) of
the Securities Act or until this  Registration  Statement shall become effective
on such date as the Securities and Exchange Commission,  acting pursuant to said
Section 8(a), may determine.

       This Post Effective  Amendment No. 2 to Form S-3  Registration  Statement
(333-53657)  is being  filed to  amend  the  current  KeySpan  Investor  Program
prospectus.   The  accompanying   prospectus  supersedes  the  Investor  Program
prospectus and prospectus  supplements  which were filed with the Securities and
Exchange  Commission  on May 27,  1998,  August 12,  1999,  December 6, 1999 and
December 13, 2001.

       The  registration  fee was paid at the time of the original filing of the
Form S-3 Registration Statement.









                           Subject to completion dated
                           ---------------------------

- --------------------------------------------------------------------------------

Investor
Program

5,000,000Common Stock,$0.01 par value per share


PROSPECTUS

                            KEYSPAN INVESTOR PROGRAM
               5,000,000 Common Stock, $0.01 par value, per share

                           INVESTOR PROGRAM HIGHLIGHTS

We are  pleased  to offer you the  opportunity  to  participate  in the  KeySpan
Investor   Program  (the   "Program")  a  direct  stock  purchase  and  dividend
reinvestment plan. The Program is designed to provide you with:

       -   A  convenient  and  inexpensive  way to  purchase  and sell shares of
           KeySpan common stock ("Common Stock").

       -   The chance to  purchase  additional  shares of Common  Stock,  and to
           reinvest all or a portion of your cash dividends.

       -   The  opportunity to make additional cash purchases of Common Stock by
           check,  money  order or  automatic  deduction  from your  checking or
           savings account at a U.S. bank or financial institution. An option to
           own and transfer  shares of Common Stock without the need for holding
           stock certificates.


                             PROGRAM ADMINISTRATION

We have appointed  EquiServe Trust Company N.A.,  ("EquiServe")  as our Transfer
Agent to administer  the Program.  All purchases of Common Stock will be made by
EquiServe  at  100%  of the  then-current  market  price  of the  Common  Stock,
calculated  as  described  in this  prospectus,  either on the open  market,  or
directly from KeySpan.

Investing  in KeySpan's  Common  Stock  involves  risks  associated  with market
fluctuations.

To the extent required by law, in certain jurisdictions,  shares offered through
the Program will be offered  through a registered  broker/dealer  to persons who
are not currently KeySpan shareholders.

These  securities  have not been approved or  disapproved  by the Securities and
Exchange  Commission  or any  state  securities  commission  nor  has  any  such
commission  passed  upon  the  accuracy  or  adequacy  of this  prospectus.  Any
representation to the contrary is a criminal offense.

KeySpan Common Stock trades on the NYSE and PSE. The ticker symbol is KSE.


                                 April ___, 2001







                                Table of Contents

About this Prospectus................................................
Profile of KeySpan Corporation.......................................
Description of the Program Summary...................................
Questions and Answers Purpose........................................
Advantages and Disadvantages.........................................
Program Administration...............................................
Eligibility..........................................................
Enrollment Procedure.................................................
Common Stock Purchases...............................................
Stock Certificates and Safe Keeping..................................
Sale of Shares.......................................................
Transfer of Shares...................................................
Option Changes and Discontinuation of Reinvestment...................
Reports to Participants..............................................
Federal income Taxes.................................................
Other Information....................................................
Use of Proceeds......................................................
Plan of Distribution.................................................
Legal Opinions.......................................................
Experts..............................................................
Incorporation of Documents by Reference..............................
Company Information Continued........................................








                              ABOUT THIS PROSPECTUS

As used in this prospectus and any prospectus supplement,  except as the context
otherwise  requires,  "we," "us," "our,"  "Company," and "KeySpan" means KeySpan
Corporation.

This  prospectus  supersedes  the Investor  Program  prospectus  and  prospectus
supplements which were filed with the Securities and Exchange  Commission on May
27, 1998, August 12, 1999 and December 6, 1999. Approximately 2.8 million shares
have been issued under the Investor  Program from May 27, 1998 through March 31,
2000.


                         PROFILE OF KEYSPAN CORPORATION

KeySpan,  a member of the S&P 500, is the largest  distributor of natural gas in
the Northeast.  KeySpan is also the largest investor-owned electric generator in
the  State of New York and  operates  Long  Island's  electric  system.  KeySpan
recently expanded its geographic range into New England with the acquisitions of
Eastern  Enterprises and  EnergyNorth.  In addition,  KeySpan markets energy and
Internet  services;  processes gas in Canada; and has investments in fiber-optic
cable,   natural-gas   exploration,    production,    pipeline   transportation,
distribution, and storage. For a more complete description, please refer to page
27.

        o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o










                                     SUMMARY

The summary highlights  selected  information from this prospectus,  but may not
contain all of the information that is important to you. To fully understand the
Program and for a more complete  description  of the legal terms of the Program,
you should read this entire  document  carefully  and the  documents to which we
have  referred  you. To find out how to obtain  copies of these  documents,  see
Question 32.


                             PURPOSE OF THE PROGRAM

The  purpose  of  the  Program  is  to  provide  our   Registered   Shareholders
(shareholders  whose stock is  registered  in their  name,  not in the name of a
broker),  our  customers  and  other  investors  with a simple,  convenient  and
economical  way to make and  increase  investments  in our  Common  Stock and to
reinvest all or a portion of any cash  dividends  paid in  additional  shares of
Common Stock. The Program also provides  participants  with an economical method
to sell shares of Common Stock.


                        HOW TO PARTICIPATE IN THE PROGRAM

New Investors

If you are not currently a KeySpan  shareholder,  you can purchase  Common Stock
for the first time with a minimum  investment of $250, with no transaction  fee.
New investors may make their initial investment in Common Stock by completing an
Initial Investment Form and either mailing it with a check or money-order for at
least $250,  or,  alternatively,  you can authorize  EquiServe to  automatically
deduct your initial  investment  from your checking or savings account at a U.S.
bank or financial institution. The automatic deduction feature also provides new
investors with the option of having a minimum of $25 deducted  either monthly or
semi-monthly, in order to reach the minimum investment of $250. However, it will
be necessary to notify EquiServe to stop making automatic deductions.

      -    New investors can also enroll on the Internet at EquiServe's web site
           at  www.equiserve.com  or the Investor Relations section of KeySpan's
           web site at www.keyspanenergy.com.

      -    New investors can reinvest  their  dividends by checking the dividend
           reinvestment option on the Initial Investment Form.

Registered Shareholders

If you  are a  Registered  Shareholder,  you  may  make  additional  investments
(minimum  of $25,  annual  maximum  of  $150,000)  by check,  money  order or by
authorizing EquiServe to automatically deduct your investment from your checking
or savings account at a U.S. bank or financial institution.

Registered  Shareholders wishing to change dividend  reinvestment options may do
so by completing  and  submitting an Enrollment  Authorization  Form, by calling
EquiServe directly at 1-800-482-3638 or via the Internet at www.equiserve.com.




Non-Registered Shareholders


      -    KeySpan shareholders holding their stock through a broker must become
           Registered  Shareholders  to  enroll  in  the  Program.  For  further
           instructions  on  how  to  participate  in the  Program,  please  see
           Question 7.

Features of the Program

      -    Automatically  reinvest  all or  part  of your  cash  dividends  to
           purchase additional shares.

      -    You do not need to reinvest your dividends to participate.  Dividends
           not reinvested  can be paid to you by check or electronic  deposit to
           your bank account.

      -    You may sell your shares of Common  Stock by  instructing  EquiServe,
           either by telephone, in writing, or through the Internet. Sale orders
           are processed daily.

     -    You may transfer shares or make gifts of shares of Common Stock easily
          and at no cost.

     -    You may make all account inquiries by telephone,  writing,  and/or via
          the Internet.

     -    Cash investments are processed weekly, usually on Thursdays.

      -    Your whole and fractional shares of Common Stock are credited to your
           account in safe and  convenient  book-entry  form.  However,  you may
           request stock certificates free of charge.

      -    For safekeeping  purposes,  stock  certificates can be converted into
           book-entry shares,  which will be credited to your account at no cost
           to you.

Fees and Commissions

      -    KeySpan  pays all  processing  fees for  initial  investments  in the
           Program,  for  additional   investments  and  dividend  reinvestments
           processed  as original  issue or  treasury  shares and for the annual
           maintenance  cost  of  your  account.  However,  should  the  Company
           purchase shares on the open market, participants will pay a brokerage
           commission of $0.05 per share.

      -    You  will  be  charged  only  the   transaction  and  brokerage  fees
           (currently  $5.00 per transaction and $0.05 per share) on the sale of
           shares of Common Stock through the Program, and brokerage commissions
           on all purchases made using open market shares  (currently  $0.05 per
           share).

     -    Returned checks or failed automatic deduction transactions will result
          in a charge of $20 to the participant.

     -    You may be  charged  $5.00  per  year  (not to  exceed  $25.00)  for a
          duplicate statement older than two calendar years.

Questions and Answers

      The following is a question and answer format  explanation  of the Program
      which provides the terms and conditions of the Program.



Purpose

1.    What is the purpose of the Program?

      The purpose of the Program is to provide Registered Shareholders of Common
      Stock and potential  investors a simple,  convenient and economical way to
      accumulate and increase  their  investment in Common Stock and to reinvest
      all or a portion of their cash  dividends in  additional  shares of Common
      Stock. The Program also provides participants with an economical method to
      sell shares of Common Stock.

Advantages and Disadvantages

2.    What are the advantages of the Program?

      The advantages of the Program are as follows:

     -    Direct Purchase of Initial Shares: Persons not presently owning shares
          of  Common  Stock  may  enroll in the  Program  by  making an  initial
          investment of at least $250, but not more than $150,000 per year.


     -    Reinvestment of Dividends: Participants may purchase additional shares
          of Common Stock automatically by reinvesting all or a portion of their
          cash  dividends.  Dividend  payments  not  reinvested  will be paid to
          participants by check or will be deposited electronically upon written
          request.


     -    Direct Purchase of Common Stock through  Additional Cash  Investments:
          Participants may purchase  additional shares of Common Stock by making
          additional  cash  investments  by  check,  money  order or  electronic
          transfer  in  amounts of at least $25 per  investment,  with a maximum
          allowable investment of $150,000 per year.

     -    Certificate  Safekeeping:  The Program offers a "safekeeping"  service
          free of charge,  whereby  Registered  Shareholders  may deposit  their
          Common Stock  certificates with EquiServe and have their  certificated
          shares  credited  to  their  account.   This  feature  prevents  stock
          certificate loss, theft or destruction.  Since deposited shares become
          Book-entry shares, they may be transferred or sold through the Program
          in a convenient and economical manner.

     -    Reduced Fees:  Fees charged to  participants  are usually less than if
          the  individual  investor  purchased  or sold  shares  outside  of the
          Program through a broker.

     -    Certificates/Transfer of Shares: Participants may request the issuance
          of stock  certificates  or  transfer to another  participant  all or a
          portion of their  Program  shares free of charge.  Stock  certificates
          will only be issued in whole share amounts.

     -    Simplified    Record-keeping:    Participants    are    furnished   an
          acknowledgment  after each purchase or sale,  quarterly statements and
          cumulative  year-end   statements  of  their  accounts,   providing  a
          simplified method of record-keeping.

3.    What are the Disadvantages of the Program?

      The disadvantages of the Program are as follows:

      -    No Interest Paid on Funds Pending Investment:  No interest is paid on
           dividends or optional  cash  investments  held by  EquiServe  pending
           investment or reinvestment.

      -    Purchase/Sale Price Determination:  Participants have no control over
           the share  price or the  timing of the sale or  purchase  of  Program
           shares. Participants cannot designate a specific price or






           a  specific  date at which to sell or  purchase  Common  Stock or the
           selection of a broker/dealer through or from whom purchases are made.
           In  addition,  participants  will not know the exact number of shares
           purchased until after the investment date.

Program Administration

4.    Who administers the Program?

      EquiServe has been  appointed as our transfer  agent,  to  administer  the
      Program. Their responsibilities include:

     -    Determining  the timing and the making of purchases of Common Stock on
          the open market

     -    Crediting  participant's accounts with shares of Common Stock acquired
          under the Program

     -    Maintaining account records and sending statements of account activity
to participants.


5.    Who should I contact with questions regarding the Program and its
      administration?

      You may contact EquiServe by writing to:
      EquiServe
      P.O. Box 2598
      Jersey City, NJ 07303-2598

      You may also contact  EquiServe  at one of the  telephone  numbers  listed
below:

     -    Shareholder customer service, including sale of shares: 1-800-482-3638
          (within the U.S. and Canada) and 1-201-324-0498  (outside the U.S. and
          Canada).


     -    New investors requesting Program material:  1-800-948-1691  (available
          24 hours, 7 days a week).


     -    TDD:  1-201-222-4955  (a  telecommunications  device  for the  hearing
          impaired is available).

      You may also contact  EquiServe  via the  Internet.  EquiServe's  Internet
      address  is  www.equiserve.com.  Messages  sent via the  Internet  will be
      responded to promptly.  At EquiServe's web site, you can access your share
      balance, sell shares, request a stock certificate, and obtain online forms
      and other information  about your account.  To get access to your account,
      you will require a password  which will be sent to you by mail, or you can
      request    your    password    by   calling    toll-free    1-877-THE-WEB7
      (1-877-843-9327).

Eligibility

6.    Am I eligible to participate in the Program?

      Any person or entity is eligible to participate in the Program, whether or
      not you currently own our Common Stock. If you are a resident of a foreign
      country,  you should  make sure that  participation  would not violate any
      laws in the country in which you reside.


Please include "KeySpan" on all  correspondence  and provide your account and/or
social security number.







Enrollment Procedure

7.    How do I become a Program participant?

      New Investors. If you do not currently own our Common Stock you may enroll
      in the Program by completing an Initial  Investment  Form. You must return
      the  completed  form to EquiServe  with an initial  investment of at least
      $250,  but no greater than  $150,000.  The payment can be in the form of a
      check or money order, made payable to  "EquiServe-KeySpan."  PLEASE DO NOT
      SEND CASH.

      You may also authorize automatic  deductions of $25 per transaction from a
      checking or savings account at a U.S. bank or financial institution either
      monthly or semi-monthly, in order to reach the minimum investment of $250.
      Automatic  deductions  will  continue  until such time as the new investor
      notifies  EquiServe  in writing to stop making  automatic  deductions.  An
      Automatic Deduction  Authorization Form is included on the reverse side of
      the Initial Investment Form.

      If you are a  Registered  Shareholder.  If you own shares of Common  Stock
      that are registered in your name, not the name of a broker, you can enroll
      in the Program by completing  and  returning an  Enrollment  Authorization
      Form to EquiServe or by calling EquiServe directly at 1-800-482-3638.  You
      may  obtain  additional  Enrollment  Authorization  Forms at any time upon
      request to EquiServe.

      If you are a Beneficial  Owner. If you are the beneficial  owner of Common
      Stock  through a bank,  broker,  or trustee,  you can become a  Registered
      Shareholder by instructing your bank,  broker, or trustee to transfer some
      or all of your  shares of Common  Stock  into your  name.  You can  choose
      whether to receive a physical stock  certificate for your shares of Common
      Stock, have them registered in the Direct Registration System in your name
      or deposit them in a book-entry account maintained by EquiServe.

      There are  several  options in which you may elect to hold your  shares of
KeySpan Common Stock:

      - Stock Certificate. Once you receive your stock certificate in your name,
      you can enroll in the Program and you may begin to use all of the services
      of the Program,  such as the dividend  reinvestment and economical selling
      of shares features.

      - Direct  Registration  System  Book-Entry  Shares.  This is an electronic
      transfer of your shares from your broker's name into your name through the
      Direct  Registration  System.  Simply  instruct your broker to conduct the
      transaction. This will establish a book-entry account at EquiServe and you
      can then commence using any or all of the Program services.

      You may also arrange to have your bank, broker, or nominee  participate in
      the Program on your behalf.  In this case,  your  participation  may be on
      terms and conditions  which differ from the terms and conditions set forth
      in this  Program  and you will be  limited  to the  dividend  reinvestment
      feature of the Program  only.  The terms and  conditions  set forth in the
      Program  will also be  subject to the terms and  conditions  of your bank,
      broker, or nominee.  EquiServe will not have a record of your transactions
      or your  account  since  they will  remain  under the name of your bank or
      broker.


8.    What are my dividend reinvestment options available under the Program?

      The following options are available to you under the Program. However, you
      must elect one of the following options on the Initial  Investment Form or
      the  Enrollment  Authorization  Form in order to have any  portion of your
      dividends  paid  to  you,  otherwise  they  will  automatically  be  fully
      reinvested to purchase additional shares of Common Stock.






      Full Dividend Reinvestment. You can opt to have all of your cash dividends
      on all  certificated  and  Program  shares of Common  Stock  automatically
      reinvested to purchase  additional  shares of Common Stock.  If you do not
      make  an  election  on the  Initial  Investment  Form  or  the  Enrollment
      Authorization  Form you  will  automatically  have  your  dividends  fully
      reinvested.

      Partial  Dividend  Reinvestment.  You may  choose  to  receive  your  cash
      dividends   on  a  specified   number  of  shares  of  Common   Stock  and
      automatically  have the cash  dividends on the remainder of your shares of
      Common Stock reinvested to purchase  additional shares of Common Stock. If
      you elect to have partial  dividend  reinvestment,  you must designate the
      number of Program shares and/or  certificated  shares for which you choose
      to receive your cash dividends in a whole number.  Cash dividends are sent
      to you by check or, upon request,  and are deposited  electronically  into
      your U.S. bank account.

      Cash Payments Only (No Dividend  Reinvestment).  You may choose to receive
      all of your dividends as a cash payment. Cash dividends are sent to you by
      check, or upon request,  are deposited  electronically into your U.S. bank
      account.  For more  information  on the  electronic  deposit of dividends,
      please refer to Question 10, or contact EquiServe.


9.    How do I make additional cash investments in Common Stock?

      You may make additional  cash  investments by choosing among the following
two options:

      Check Investment. You may make additional cash investments in Common Stock
      by  sending  to  EquiServe  a check,  money  order,  or bank draft for the
      purchase of additional shares of Common Stock. The check,  money order, or
      bank draft must be made payable to  "EquiServe - KeySpan" in U.S.  dollars
      and drawn on a U.S. bank. If you are not in the U.S., contact your bank to
      verify that they can  provide you with a check that clears  through a U.S.
      bank and can print the  dollar  amount in U.S.  funds.  Due to the  longer
      clearance period, we are unable to accept checks clearing through non-U.S.
      funds.  EquiServe  will not accept third party checks.  All checks,  money
      orders,  and bank drafts should be sent to EquiServe at the address listed
      on the tear-off  form attached to each account  statement you receive,  or
      with your Initial Investment Form or Enrollment Authorization Form.

      Automatic  Investment  from a Bank Account.  As an  alternative to sending
      checks, money orders, and bank drafts for additional cash investments, you
      may elect to have funds  automatically  withdrawn  from your  checking  or
      savings account at a U.S. bank or financial institution. You may elect the
      automatic   deduction  option  by  completing  and  signing  an  Automatic
      Deductions  Authorization  Form  and  returning  this  form to  EquiServe,
      together with a voided blank check or savings account deposit slip for the
      bank  account  from  which  the  funds  are  to be  withdrawn.  Additional
      Automatic Deductions  Authorization Forms are available through EquiServe.
      Your Automatic  Deductions  Authorization  Form will be processed and will
      become  effective as promptly as  practicable.  However,  you should allow
      four to six weeks for the first  investment  to be  initiated  using  this
      automatic deduction feature.  Once automatic  deductions begin, funds will
      be withdrawn  from your bank account on either the first or fifteenth  day
      of each month,  or both (at your  option),  or on the next business day if
      either of those days is not a business day. You may change or  discontinue
      automatic  deductions  by  completing  and  submitting  to EquiServe a new
      Automatic Deductions Authorization Form.

      Brokers  or  bank  nominees  participating  on  behalf  of  Non-Registered
      Shareholders or beneficial  owners may only use the dividend  reinvestment
      feature  of the  Program  and cannot use the  additional  cash  investment
      feature.  If a  Non-Registered  Shareholder  wishes to  participate in the
      additional  cash investment  feature of the Program,  he or she must first
      become a Registered Shareholder or make an






      initial investment to enroll directly in the Program.


10.        Can my cash dividends be deposited directly to my bank account?

      Yes,  you may elect to have any cash  dividends  which are not  reinvested
      paid by electronic  funds transfer to your U.S. bank account.  To do this,
      you must first complete and return a Direct Deposit  Authorization Form to
      EquiServe  along with a copy of a voided  blank  check or savings  account
      deposit slip.  This form is not included  with your Program  materials and
      must be specifically requested from EquiServe at 1-800-870-2340.


11.        What are the minimum and maximum amounts for additional cash
investments?

      In addition  to  increasing  your  holdings  of Common  Stock  through the
      reinvestment of dividends,  you may make  additional  cash  investments in
      Common Stock at any time. Your additional cash investments by check, money
      order,  or  automatic  deductions  must be at  least  $25  with a  maximum
      allowable  investment  of $150,000  per  calendar  year.  If you are not a
      Registered  Shareholder and are a first time investor in the Program, your
      initial  investment must be for at least $250 and cannot exceed  $150,000.
      See Question 7 regarding new investors.


Common Stock Purchases

12.        What are the sources of Common Stock purchased under the Program?

      Shares of Common  Stock will be purchased  either on the open  market,  or
      directly from KeySpan, from shares held in our treasury or as newly issued
      shares, or a combination of the foregoing. You cannot choose the source of
      your shares purchased since this is entirely at our discretion.

      Shares  purchased  on the open  market  may be made on any stock  exchange
      where our Common Stock is traded or by  negotiated  transactions  on terms
      that  EquiServe  may  reasonably  determine.  Should the Company  purchase
      shares on the Open Market, participants will pay a brokerage commission of
      $0.05  per  share.  Neither  KeySpan  nor any  participant  will  have any
      authority or power to direct the date,  time,  or price at which shares of
      Common  Stock may be  purchased,  or the  selection  of a broker or dealer
      through or from whom purchases are made.


13.        When will shares be purchased under the Program?

      - General.  Direct purchases from KeySpan's authorized but unissued shares
      of Common  Stock will  normally be made on a weekly  basis on the relevant
      "investment  date,"  (usually  Thursdays)  or the next  trading day if the
      investment  date is not a trading  day.  Purchases on the open market will
      begin on the  investment  date and will be completed no later than 30 days
      from such date,  except where  completion  at a later date is necessary or
      advisable under any applicable federal securities law.

      - Cash  Investments.  EquiServe  will  normally  invest  any  initial  and
      additional  cash  investments for the purchase of Common Stock on a weekly
      basis, usually on Thursdays, after receipt of the check, money order, bank
      draft  or  automatic  deduction.   EquiServe  will  determine  the  actual
      investment  date for initial and additional cash  investments,  and should
      receive  payment  no later  than 2  business  days  prior  to each  week's
      investment date. However, it should be noted that there is no guarantee of
      the date on which  investments  will be made,  or if your  payment will be
      received on time for that week' s






      investment.

      - Dividend  Reinvestments.  The investment date for dividend reinvestments
      will be the dividend payment date or the next business day if the dividend
      payment date is not a business day. If EquiServe  receives your Enrollment
      Authorization  Form requesting  reinvestment of dividends on or before the
      record date  established  for a  particular  dividend,  reinvestment  will
      commence  with  that  dividend.  If  EquiServe  receives  your  Enrollment
      Authorization  Form requesting  reinvestment of dividends after the record
      date established for a particular dividend,  you will be paid the dividend
      in cash and your reinvestment of dividends will begin on the next dividend
      payment date.

      The  anticipated  payment  dates for Common Stock are usually on the first
      business day of February,  May, August, and November. The record dates for
      Common Stock are usually on the 15th day of  February,  May,  August,  and
      November.  It is  anticipated  that  record  dates and  payment  dates for
      dividends that we may declare in the future will be at  approximately  the
      same times of the year.


14.        How is the purchase price of the Common Stock determined?

      The  purchase  price of Common  Stock  purchaseddirectly  from  KeySpan,as
      treasury shares or original issue shares,  will be the average of the high
      and low  prices of the  Common  Stock as  reported  in the New York  Stock
      Exchange composite transactions for that investment date.

      The  purchase  price of Common  Stock  purchased on the open market is the
      weighted  average of the  actual  purchase  price of all shares  purchased
      during the applicable  investment period. The price is adjusted to include
      brokerage  commissions  of $0.05 per  share.  Open  market  purchases  are
      expected to be made through EquiServe.

      A Program participant will have the applicable  commissions  deducted from
      the funds used to purchase shares acquired under the Program, see Question
      25.

      You cannot  request a specific  purchase  price,  date,  quantity,  and/or
purchase by a specific broker.


15.        How many shares of Common Stock will be purchased for me?

      The number of shares purchased for you will be equal to the amount of your
      additional   cash   investments,   plus  any   dividends   available   for
      reinvestment,  or the initial investment  received by EquiServe during the
      investment period, less any applicable fees, divided by the purchase price
      of the shares.  Your account will be credited with the number of shares of
      Common  Stock,  including  fractional  shares  computed  to three  decimal
      places.

16.        Will I be paid interest on any amounts pending the actual investment
date?

          No.  Interest  will  not be paid on  amounts  sent  to  EquiServe  for
          investment pending the actual investment date.


Stock Certificates and Safe Keeping

17.        Will I be issued stock certificates for shares of Common Stock
purchased through the Program?

          No. Shares of Common Stock  purchased  through the Program will not be
          issued to you in stock






      certificate  form,  but will be  credited to your  account--as  book entry
      shares --by EquiServe on your behalf. The number of shares of Common Stock
      credited to your account will be shown on your account statement.


18.        How may I receive a stock certificate?

      You may obtain a stock certificate at no cost for some or all of the whole
      shares credited to your account at any time by simply requesting EquiServe
      to  withdraw  shares  from  your  account  and  to  issue  them  in  stock
      certificate form. You may make such a request by:

          --Calling EquiServe at 1-800-482-3638;
           --Accessing your account through the Internet at EquiServe's web site
           www.equiserve.com;  --Using the tear-off form attached to the account
           statement; or --Sending written notice specifying the number of whole
           shares to be withdrawn.

      Stock  certificates  will be issued to you and  registered  in your  name.
      Stock certificates are normally issued to participants within two business
      days after receipt of a request.  No stock certificates will be issued for
      a fractional share of Common Stock. If you request a stock certificate for
      all shares credited to your account,  a stock  certificate  will be issued
      for the whole  shares and a cash  payment  will be made for any  remaining
      fractional  shares.  That cash payment will be based upon the then-current
      market price of the Common  Stock,  less any service  fee, any  applicable
      brokerage commission, and any other costs of sale.

      Withdrawing  shares from your account into stock certificate form does not
      affect your dividend  reinvestment  option. For example, if you authorized
      the full dividend  reinvestment  option,  cash dividends,  with respect to
      shares  withdrawn  from  your  account  in stock  certificate  form,  will
      continue to be reinvested.


19.        May I add my shares of Common Stock held in stock certificate form to
my account with EquiServe for safekeeping purposes?

      Yes, you may deposit any Common Stock  certificate in your  possession and
      registered  in your name with  EquiServe  for  credit to your  account  as
      book-entry  shares at any time,  at no cost. We will pay all fees for this
      service. This safekeeping feature offers two advantages:

      -  The  risk  associated  with  loss,   theft,  or  destruction  of  stock
      certificates  is  eliminated;  otherwise,  in the case of a lost or stolen
      stock  certificate,  no sale or transfer may occur until a replacement  is
      obtained, which can be a costly and time-consuming process; and

      - Since shares  deposited  into your account with EquiServe are treated in
      the same  manner as shares  purchased  through  the  Program,  they may be
      transferred  or sold  through the Program in a  convenient  and  efficient
      manner.

      To combine shares held in stock  certificate  form with shares credited to
      your account,  you must send your request and your stock  certificates  to
      EquiServe.  The stock certificates should not be endorsed.  EquiServe will
      promptly send you a statement confirming each stock certificate deposited.

      To insure  against loss  resulting  from  mailing  stock  certificates  to
      EquiServe,  the Program provides for mail insurance,  free of charge,  for
      stock  certificates  valued up to $25,000  current  market value  (maximum
      coverage) when mailed first class, using a brown,  pre-addressed  envelope
      provided by






      EquiServe.   Envelopes   may  be   obtained   by  calling   EquiServe   at
      1-800-482-3638.  For information  about mailing stock  certificates  which
      have a current  market  value in excess of  $25,000,  you  should  contact
      EquiServe.  To be eligible for stock certificate  mailing  insurance,  you
      must  notify  EquiServe  of any lost  stock  certificate  claim  within 30
      calendar days of the date the stock certificates were mailed.

      Mail insurance covers the replacement of shares of Common Stock, but in no
      way protects you against any loss resulting from fluctuations in the value
      of the shares from the time you mail the stock certificates until the time
      replacement can be made. If you do not use a brown, pre-addressed envelope
      provided  by  EquiServe,  you should send your stock  certificates  to the
      address listed in Question 5 by registered mail, return receipt requested,
      and insure for  possible  mail loss for 2%  (minimum of $20) of the market
      value.  This  represents the  approximate  cost to you of replacing  stock
      certificates if they are lost or stolen.


Sale of Shares

20.        How can I sell Program shares?

      To sell any shares  that you hold in stock  certificate  form  through the
      Program,  the shares must first be converted  into  book-entry  shares and
      credited to your  account with  EquiServe.  You can sell any of the shares
      credited  to  your  account  with   EquiServe  by  calling   EquiServe  at
      1-800-482-3638,    accessing    your   account   via   the   Internet   at
      www.equiserve.com,   by  writing  to  EquiServe,   or  by  completing  and
      submitting the tear-off portion of your account statement.


21.        How is the sale price of Program shares determined?

      EquiServe  aggregates all requests to sell shares and then sells the total
      share amount on the open market. Upon receipt of your request to sell some
      or all of your  shares,  EquiServe  will make every  reasonable  effort to
      process all sales orders on the day the orders are received. To do so, you
      must ensure that instructions are received before 1:00 p.m. (Eastern Time)
      on a business day during which  EquiServe and the New York Stock  Exchange
      are  open.  Sales  will be made at the  then-current  market  price of the
      Common Stock and EquiServe will promptly mail you a check.  The check will
      be for the net cash  proceeds  of the sale,  minus a service  fee of $5.00
      plus  brokerage  commissions  of  $0.05  per  share.  EquiServe  has  full
      discretion in all matters related to the sale,  including the time of sale
      and sales price and the selection of a broker.  You cannot specify a price
      or a time at which to sell your book-entry shares.

      You should be aware that the Common  Stock  price may rise or fall  during
      the period  between a request for sale,  its receipt by EquiServe  and the
      ultimate sale on the open market.  Instructions  sent to EquiServe to sell
      shares are irrevocable and may not be rescinded.


Transfer of Shares

22.       Can I assign or transfer all or a part of my Program shares to another
person?

Yes. You may change  ownership of all or part of your Program  shares  through a
gift, sale or otherwise at any time. You may contact EquiServe at 1-800-482-3638
for  complete  transfer  instructions  and you will be  asked to send  EquiServe
written transfer  instructions to enact the transfer.  Requests for transfer are
subject to the same  requirements  as for the  transfer  of stock  certificates,
including the requirement of a






Medallion Signature Guarantee.


23.        If Program shares are transferred to another person, will EquiServe
issue a stock certificate to the transferee?

          No.  Transfers  will be credited to an account in book entry form.  If
          you so request,  a stock  certificate can be issued to the transferee.
          You  should  contact  EquiServe  for full  details  on how to make the
          transfer.

          For book entry  transfers  that  involve  the  establishment  of a new
          account,  the completed  Initial  Investment  Form must be returned to
          EquiServe,  along  with  written  instructions  signed by the  current
          participant,  indicating the number of shares to be transferred to the
          transferee.  The current participant's signature must be guaranteed by
          a bank,  broker  or  financial  institution  that is a  member  of the
          Medallion Signature Guarantee Program.  The new account will be set up
          for full  dividend  reinvestment  unless  otherwise  instructed by the
          previous or new shareholder.


Option Changes and Discontinuation of Reinvestment

24.        How can I change my dividend reinvestment option or discontinue
reinvesting my dividends?

          You may change  dividend  reinvestment  options  by calling  EquiServe
          directly at 1-800-482-3638,  instructing EquiServe in writing, through
          the  Internet  or by  submitting  to  EquiServe  a new  election on an
          Enrollment   Authorization  Form.  To  be  effective  for  a  specific
          dividend,  any change must be received by EquiServe  before the record
          date for that  dividend--see  Question  13 for  information  regarding
          record dates.

          You may  discontinue  reinvestment  of cash  dividends  at any time by
          calling or writing  EquiServe  or through the  Internet.  If EquiServe
          receives your request to discontinue dividend reinvestment on or after
          the record date for a dividend,  EquiServe may either pay the dividend
          in cash or reinvest it under the Program on the next  investment  date
          on your behalf. If reinvested, EquiServe may sell the shares purchased
          and send  the  proceeds  to you,  less any  service  fees  applicable,
          brokerage  commissions and other costs of sale.  After processing your
          request to discontinue dividend  reinvestment,  any shares credited to
          your account will continued to be held in book-entry  form.  Dividends
          on any shares  credited in book-entry  form and on any shares you hold
          in  stock  certificate  form  will be paid  in  cash  by  check  or by
          electronic  funds transfer.  To have dividends  deposited  directly to
          your U.S bank account, see Question 10.


25.        Are there any fees charged to me as a Program participant?

Please refer to the tabular summary of Program fees that follows:

                         Summary of Fees and Commissions

Transaction                                               Fees/Commissions
- --------------------------------------------------------------------------
Initial Enrollment Fee                                       None
Additional Investment Purchase
(by check, money order or automatic deductions)
Sources of Shares
- -----------------
 - Original Issue                                            None
 - Treasury                                                  None
 - Open Market                                               $0.05 per share
Reinvestment of Dividends Fee
Sources of Shares
 - Original Issue                                            None
 - Treasury                                                  None
 - Open Market                                               $0.05 per share
Selling Program Shares                                   $5.00 + $0.05 per share
Issuance of Certificates                                     None
Deposit of Certificates                                      None
Transfers of Shares                                          None
Returned checks or failed automatic deductions               $20.00
Duplicate Statements                                         $5.00 per year
(2 years or older)                                        (not to exceed $25.00)


Reports to Participants

26.        What kind of reports will I be sent?

      To  assist  you in  your  record  keeping,  EquiServe  will  send  you the
following information:

      -    A  statement   detailing  the  transactions  for  each  initial  cash
           investment,  additional cash purchase, sale or transfer that you make
           or receive;

      - For each dividend reinvested, a statement detailing all activity in your
account for that quarter;

      -    For any transactions you make after the fourth quarter  dividend,  an
           updated cumulative  statement  detailing all activity in your account
           for that year;

      You should retain these statements for tax purposes.

      -    You will  also be sent  copies  of the  communications  sent to other
           shareholders.  These include  KeySpan's  annual  reports,  notices of
           annual meeting and proxy statements,  company updates, and income tax
           information  for reporting  dividends paid and proceeds from the sale
           of  Program  shares.  However,  if you  are a  beneficial  owner  who
           participates  through a broker or bank  nominee,  you should  contact
           your broker or bank  nominee for a statement  detailing  reinvestment
           activity.


Federal Income Taxes

27.        What are the Federal Income Tax consequences of participation in this
Program?

      This is a general  discussion of the U.S.  federal income tax consequences
      of the  program.  You should  consult your own tax advisor with respect to
      the tax consequences of participation in the program  (including  federal,
      state,  local and other tax laws and U.S.  withholding laws) applicable to
      your particular situation.

      You will not realize  gain or loss for U.S.  federal  income tax  purposes
      upon a  transfer  of shares to your  account  or the  withdrawal  of whole
      shares from your account.







      You will  generally  realize  gain or loss upon the  receipt of cash for a
      fractional  share credited to your account.  You will also realize gain or
      loss  when  shares  are  sold.  The  amount  of gain  or loss  will be the
      difference  between  the amount  that you  receive for the shares sold and
      your tax  basis  in the  shares,  generally  the  amount  you paid for the
      shares. In order to determine the tax basis for shares in your account you
      should retain all account statements.

      Generally, cash dividends reinvested under the program will be taxable for
      U.S.  federal  income tax  purposes  as having  been  received by you even
      though you have not actually  received  them in cash.  The total amount of
      dividends paid to you during the year, whether or not they are reinvested,
      will be  reported to you and the U.S.  Internal  Revenue  Service  shortly
      after the close of each year.

      If you are a nonresident  foreign  stockholder whose dividends are subject
      to U.S.  federal  income  tax  withholding,  the  amount  of the tax to be
      withheld  will be deducted  from the amount of dividends to determine  the
      amount of dividends to reinvest.

      Dividends  paid on shares in the  accounts  may be subject to "the  backup
      withholding"  provisions of the Internal  Revenue Code. If you are subject
      to  backup  withholding,  EquiServe  must  withhold  and  pay  over to the
      Internal Revenue Service 31% from the amount of dividends, the proceeds of
      the  sale of a  fractional  share  and the  proceeds  of any sale of whole
      shares, unless you are exempt from the withholding  requirements described
      in Section 3406 of the Internal Revenue Code.

Other Information

28.      What happens if KeySpan issues a stock dividend, declares a stock split
or has a rights offering?

      All stock  dividends  or split  shares  distributed  by  KeySpan on shares
      credited to your account and/or on shares held by you in the form of stock
      certificates will be credited directly into your account. You will receive
      a  statement  indicating  the  number of shares or  dividends  earned as a
      result  of  the  transactions.   This  includes   entitlements  on  shares
      calculated on book-entry shares and certificated shares registered in your
      name. In the case of a rights  offering,  your rights will be based on the
      full shares  credited to your account  and/or on shares held by you in the
      form of stock certificates.

29.             How will my shares be voted?

      For any  meeting  of Common  Stock  shareholders,  all  participants  will
      receive  proxy  materials  including  a proxy card  representing  both the
      shares for which you hold stock certificates and the whole shares credited
      to your  account.  All shares will be voted as designated by you or may be
      voted in person at shareholder meetings.

30.        What are not the responsibilities of KeySpan and EquiServe under the
Program?            ---

      In administering the Program, KeySpan and EquiServe will not be liable for
      any of the following acts done in good faith:

      -    Any claim of liability  with respect to the shares of Common Stock of
           a  deceased  participant's  account  prior to  receipt  in writing of
           instructions relating to the disposition of such shares;

      -    With  respect  to the  prices at which  shares  of  Common  Stock are
           purchased  or sold for the  participant's  account and the times when
           such purchases or sales are made;

     -    With  respect to any  fluctuation  in the market value before or after
          any purchase or sale of shares of Common Stock.







      Holding Common Stock under the Program is no different than holding shares
      on your own.  Neither  KeySpan  nor  EquiServe  assure  you of a profit or
      protect you from any losses  sustained  on the  purchase  of Common  Stock
      under the Program.

31.        May the Program be changed or discontinued?

      We reserve the right to amend, suspend,  discontinue or modify the Program
      at  any  time  without  the  approval  of  participants.   Notice  of  our
      determination to suspend,  discontinue or modify the Program will be given
      to  all  Program   participants   as  soon  as   practicable   after  such
      determination  is made.  Changes or  discontinuation  will not affect your
      rights as a shareholder in any way and any book-entry  shares you own will
      continue to be credited to your account  unless you  specifically  request
      otherwise.

32.        Where can I find more information on KeySpan?

      We file annual,  quarterly and special reports, proxy statements and other
      information  with the SEC. You may read and copy any of these documents at
      the SEC 's public  reference  rooms in Washington,  D.C.,  Chicago and New
      York.

      Washington, D.C.
      Judiciary Plaza
      450 Fifth Street, N.W.
      Washington, D.C. 20549

      Chicago, Illinois
      SEC Regional Office
      500 West Madison Street
      Chicago, IL 60661

      New York SEC
      Regional Office
      7 World Trade Center
      New York, NY 10048

      Please  call the SEC at  1-800-SEC-0330  for  further  information  on the
      public  reference  rooms. Our SEC filings are also available to the public
      on the SEC's web site at  http://www.sec.gov.  KeySpan  is  subject to the
      reporting  requirements  of the  Securities  Act of 1934. In accordance to
      this Act, the Company files reports and other information with the SEC.

      You may also  request  copies of our 10K,  10Q,  annual  reports and proxy
      statements directly from KeySpan by:

      Mail:
      KeySpan Corporation
      Investor Relations
      One MetroTech Center, 22nd Floor
      Brooklyn, NY 11201
      Telephone: 718-403-3196
      Internet: www.keyspanenergy.com
                ---------------------
      (Investor Relations Section)



                                 USE OF PROCEEDS


The Program provides for, and we currently  contemplate,  the issuance of Common
Stock  directly  from the  Company  either  from  shares  held in the  Company's
treasury or as newly issued  shares.  The Program also provides for the purchase
of Common Stock on the open market by an agent  independent  of the Company.  To
the extent that shares of Common Stock are purchased  directly from the Company,
the net  proceeds are expected to be used for general  corporate  purposes.  The
Company  cannot  estimate  the number of shares of Common Stock that the Company
will sell  through  the Program or the prices at which such shares will be sold.
Should  Program  shares be purchased  on the open  market,  the Company will not
receive any of the proceeds  from the sale of such shares.  The Company does not
expect to change the source of Program shares frequently and will not do so more
than  once in any three  month  period  or such  other  period of time as may be
permitted under future SEC regulations.


                              PLAN OF DISTRIBUTION

The  shares of Common  Stock will be offered  directly  to Program  participants
without underwriters as described in this prospectus.


                                 LEGAL OPINIONS

The validity of the Common Stock offered by us in this prospectus will be passed
upon for us by Steven L. Zelkowitz, Senior Vice President and General Counsel of
KeySpan Energy.  Mr.  Zelkowitz is the beneficial  owner of or has the option to
acquire approximately 337,500 shares of our Common Stock.


                                     EXPERTS

Arthur Andersen LLP, independent  accountants,  audited the financial statements
for the nine months ended  December 31, 1998,  the twelve months ended  December
31, 1999, and the twelve months ended  December 31, 2000, and related  schedules
incorporated by reference in this  prospectus.  These documents are incorporated
by reference  herein in reliance upon the  authority of Arthur  Andersen LLP, as
experts in accounting and auditing in giving the reports.


                     INCORPORATION OF DOCUMENTS BY REFERENCE

We file  annual,  quarterly  and special  reports,  proxy  statements  and other
information  with the SEC.  You may read and copy any of these  documents at the
SEC's public reference rooms in Washington,  D.C., NewYork, NewYork and Chicago,
Illinois.  Please call the SEC at 1-800-SEC-0330 for further  information on the
public  reference rooms. Our SEC filings are also available to the public on the
SEC's web site at http://www.sec.gov.

We filed a registration statement on Form S-3, as amended, with the SEC covering
the common stock. For further information on us and the Common Stock, you should
refer to the registration statement,  as amended, and its exhibits.  Because the
prospectus may not contain all the information that you may find important,  you
should review the full text of these documents. We have included copies of these
documents in an exhibit to our registration statement, as amended, of which this
prospectus is a part.

The SEC allows us to  "incorporate  by reference" the  information  that we file
with the SEC, which means that we can disclose  important  information to you by
referring you to those documents.  The information  incorporated by reference is
considered to be part of this prospectus, and later information that the we file
with the SEC will  automatically  update  and  supersede  this  information.  We
incorporate by reference the






documents  listed below and any future  filings made with the SEC under Sections
13(a),  13(c), 14, or 15(d) of the Securities  Exchange Act of 1934 until all of
the securities are sold.

Our Annual Report on Form 10-K for the fiscal year ended  December 31, 2000; Our
Quarterly  Report on Form 10-Q for the  quarterly  periods ended March 31, 2000,
June 30, 2000 and September 30, 2000;

Our Current  Reports on Form 8-K dated March 30,1999  (which  contains the Right
Agreement between the Company and the Rights Agent),  January 19, 2000,  January
27,  2000,  February 1, 2000,  March 27,  2000,  July 12,  2000,  July 26, 2000,
October 6, 2000,  November  9, 2000,  November  20,  2000,  November  21,  2000,
December 11, 2000 and January 25, 2001.
Our Form 8-A filed May 26, 1998  pursuant to Section  12(b) of the Exchange Act.
which provides a description of the Company's common stock.

You may request a copy of these  filings,  at no cost,  over the Internet at our
web site at www.keyspanenergy.com or by writing or calling us at:

                               Investor Relations
                               KeySpan Corporation
                              One MetroTech Center
                            Brooklyn, New York, 11201
                                 (718) 403-3196

You should rely only on the information incorporated by reference or provided in
this prospectus or any supplement. We have not authorized anyone else to provide
you with different information.

We also  undertake  to provide  without  charge to each person to whom a copy of
this prospectus has been delivered, upon the written or oral request of any such
person,  a copy of any or all of the  documents  and exhibits  referred to above
which have been or may be incorporated by reference in this prospectus. Exhibits
not specifically incorporated herein by reference will be furnished upon payment
of 25 cents per page.  Requests  for such copies  should be directed to Investor
Relations,  KeySpan Corporation, One MetroTech Center, 22nd Floor, Brooklyn, New
York 11201.


                          COMPANY INFORMATION CONTINUED

KeySpan Corporation, a New York corporation, was formed on May 1998, as a result
of the business  combination  of KeySpan Energy  Corporation,  the parent of The
Brooklyn Union Gas Company,  and certain  businesses of the Long Island Lighting
Company. On November 8, 2000, we acquired Eastern  Enterprises,  a Massachusetts
business  trust,   and  the  parent  of  several  gas  utilities   operating  in
Massachusetts.  Also, on November 8, 2000, Eastern acquired  EnergyNorth,  Inc.,
the parent of a gas utility  operating in central New Hampshire.  As a result of
the acquisitions, we now have assets of more than $11 billion and have increased
our customer base by approximately 800,000 New England customers, for a total of
2.4 million gas customers throughout the Northeast.

Our core  business  is gas  distribution,  conducted  by our six  regulated  gas
utility  subsidiaries:  The  Brooklyn  Union Gas Company  d/b/a  KeySpan  Energy
Delivery New York and KeySpan Gas East Corporation d/b/a KeySpan Energy Delivery
Long Island distribute gas to customers in the Boroughs of Brooklyn,  Queens and
Staten  Island in New York City and the  Counties  of Nassau and Suffolk on Long
Island,  respectively;  Boston Gas  Company,  Colonial Gas Company and Essex Gas
Company, each doing business as KeySpan Energy Delivery New England,  distribute
gas to customers in eastern and central  Massachusetts;  and EnergyNorth Natural
Gas, Inc. d/b/a KeySpan Energy Delivery New England distributes gas to customers
in central New Hampshire and throughout the Northeast.






We are also a major, and growing,  generator of electricity.  We own and operate
five large  generating  plants and 42 smaller  facilities  in Nassau and Suffolk
Counties on Long Island and lease and operate a major  facility in Queens County
in New York City. Under  contractual  arrangements,  we provide power,  electric
transmission and distribution services,  billing and other customer services for
approximately one million electric  customers of the Long Island Power Authority
on Long Island.

Our other  subsidiaries  are involved in oil and gas exploration and production;
gas storage; wholesale and retail gas and electric marketing; appliance service;
heating,  ventilation  and air  conditioning  installation  and services;  large
energy-system  ownership,   installation  and  management;   telecommunications;
energy-related  internet  activities;  fuel  cells;  water  barging  activities,
including the hauling of fuel and other cargo; transportation by truck of liquid
natural gas and propane;  and providing meter reading  equipment and services to
municipal  utilities.  We also invest and  participate  in the  development  of,
pipelines and other energy-related projects, domestically and internationally.

We are a registered holding company under the Public Utility Holding Company Act
of 1935, as amended. Therefore, our corporate and financial activities and those
of our subsidiaries (including their ability to pay dividends to us) are subject
to  regulation  by the  Securities  and Exchange  Commission.  Under our holding
company structure,  we have no independent operations or source of income of our
own and conduct  substantially  all of our operations  through our  subsidiaries
and, as a result,  we depend on the earnings and cash flow of, and  dividends or
distributions  from, our subsidiaries to provide the funds necessary to meet our
debt and  contractual  obligations.  Furthermore,  a substantial  portion of our
consolidated  assets,  earnings and cash flow is derived from the  operations of
our regulated  utility  subsidiaries,  whose legal authority to pay dividends or
make other  distributions  to us is subject to  regulation  by state  regulatory
authorities.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS


Item 14.  Other Expenses of Issuance and Distribution.

SEC Registration Fee.....................................................$51,625
Listing Fee -- New York Stock Exchange...................................$25,650
Accounting Fees..........................................................$20,000
Legal Services and Disbursements.........................................$15,000
Printing Expenses.......................................................$125,000
Service Charge, including postage--Transfer Agents fees.................$675,000
Miscellaneous Expenses...................................................$50,000
Total Expenses..........................................................$962,275

Item 15. Indemnification of Directors and Officers.

           The New York Business  Corporation  Law ("BCL"),  Article 7, Sections
721-726 provide for the  indemnification and advancement of expenses to officers
and  directors.  Section  721  provides  that  indemnification  and  advancement
pursuant to the BCL are not exclusive of any other rights an officer or director
may be entitled to, provided that no indemnification may be made to or on behalf
of any director or officer if a judgment or other final adjudication  adverse to
the director or officer establishes that his acts were committed in bad faith or
were the result of active and  deliberate  dishonesty  and were  material to the
cause of  action  so  adjudicated,  or that  the  director  personally  gained a
financial profit or other advantage to which he or she was not legally entitled.

          Section 722 of the BCL provides  that a  corporation  may indemnify an
          officer or director, in the






case  of  third  party  actions,  against  judgments,  fines,  amounts  paid  in
settlement  and  reasonable  expenses  and, in the case of  derivative  actions,
against  amounts paid in settlement and reasonable  expenses,  provided that the
director  or  officer  acted  in  good  faith,  for a  purpose  which  he or she
reasonably  believed to be in the best interests of the corporation  and, in the
case of criminal  actions,  had no  reasonable  cause to believe his conduct was
unlawful.  In  addition,  statutory  indemnification  may  not  be  provided  in
derivative  actions  (i) which are settled or  otherwise  disposed of or (ii) in
which the director or officer is adjudged liable to the corporation,  unless and
only to the extent a court  determines  that the person is fairly and reasonably
entitled to indemnity.

           Section 723 of the BCL provides  that  statutory  indemnification  is
mandatory  where the director or officer has been  successful,  on the merits or
otherwise,  in the defense of a civil or criminal action or proceeding.  Section
723 also  provides  that  expenses of  defending  a civil or criminal  action or
proceeding may be advanced by the corporation  upon receipt of an undertaking to
repay them if and to the  extent the  recipient  is  ultimately  found not to be
entitled to indemnification. Section 725 provides for repayment of such expenses
when the  recipient is ultimately  found not to be entitled to  indemnification.
Section 726 provides that a  corporation  may obtain  indemnification  insurance
indemnifying itself and its directors and officers. The registrant has in effect
insurance  policies providing both directors and officers liability coverage and
corporate reimbursement coverage.


           Section 402(b) of the BCL provides that a corporation  may include in
its  certificate of  incorporation  a provision  limiting or  eliminating,  with
certain exceptions,  the personal liability of directors to a corporation or its
shareholders  for  damages  for  any  breach  of  duty  in  such  capacity.  The
certificate of incorporation of the registrant contains  provisions  eliminating
the personal liability of directors to the extent permitted by New York law.

           The registrant's certificate of incorporation provides generally that
it shall,  except to the extent expressly  prohibited by the BCL, indemnify each
of its  officers  and  directors  made or  threatened  to be made a party to any
action,  suit or  proceeding,  or appeal  thereof,  whether civil or criminal by
reason of the fact that such person is or was an officer or director against all
expense,  liability and loss (including, but not limited to all attorneys' fees,
judgments, fines, pension plan taxes or penalties and amounts paid or to be paid
in  settlement)  reasonably  incurred or  suffered by such person in  connection
therewith. The certificate of incorporation further provides for advancement and
reimbursement  of such expenses  incurred by an officer or director in defending
any  action or  proceeding  in  advance of the final  disposition  thereof  upon
receipt of an  undertaking  by such  person to repay such  amount if, and to the
extent  that,   such  person  is   ultimately   found  not  to  be  entitled  to
indemnification.

Item 16. List of Exhibits.

      See Exhibit Index

Item 17. Undertakings.

(a) The undersigned registrant hereby undertakes:

      (1) To file,  during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:

          (i) To include  any  prospectus  required  by Section  10(a)(3) of the
     Securities Act of 1933;

          (ii) To reflect in the  prospectus  any facts or events  arising after
     the  effective  date of the  registration  statement  (or the  most  recent
     post-effective amendment thereof) which, individually or in






      the aggregate, represent a fundamental change in the information set forth
      in the registration statement. Notwithstanding the foregoing, any increase
      or decrease in volume of securities  offered (if the total dollar value of
      securities  offered  would not exceed that which was  registered)  and any
      deviation from the low or high end of the estimated maximum offering range
      may be  reflected  in the form of  prospectus  filed  with the  Commission
      pursuant  to Rule 424(b) if, in the  aggregate,  the changes in volume and
      price  represent  no  more  than a 20%  change  in the  maximum  aggregate
      offering price set forth in the "Calculation of Registration Fee" table in
      the effective registration statement;

          (iii) To include any material  information with respect to the plan of
     distribution not previously disclosed in the Registration  Statement or any
     material  change  to  such  information  in  the  Registration   Statement;
     provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if
     the  Registration  Statement is on Form S-3,  Form S-8, or Form F-3 and the
     information required to be included in a post-effective  amendment by those
     paragraphs is contained in periodic  reports filed with or furnished to the
     Securities and Exchange  Commission by the Issuer pursuant to Section 13 or
     Section 15(d) of the Securities  Exchange Act of 1934 that are incorporated
     by reference in the Registration Statement.

      (2)  That,  for  the  purpose  of  determining  any  liability  under  the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

      (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.

(b)  The  undersigned   registrant  hereby  undertakes  that,  for  purposes  of
determining  any liability  under the Securities Act of 1933, each filing of the
Issuer's  annual  report  pursuant  to  Section  13(a) or  Section  15(d) of the
Securities  Exchange  Act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
registration  statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification  for liabilities arising under the Securities Act
of 1933 may be permitted to directors,  officers and controlling persons of such
registrant   pursuant  to  the  provisions  referred  to  in  Item  15  of  this
registration  statement,  or otherwise,  the registrant has been advised that in
the opinion of the Securities and Exchange  Commission such  indemnification  is
against public policy as expressed in such Act and is, therefore, unenforceable.
In the event that a claim for  indemnification  against such liabilities  (other
than the payment by such registrants of expenses incurred or paid by a director,
officer or controlling  person of such registrants in the successful  defense of
any  action,  suit or  proceeding)  is  asserted  by such  director,  officer or
controlling  person in connection  with the  securities  being  registered,  the
registrant  will,  unless in the  opinion  of its  counsel  the  matter has been
settled by controlling precedent,  submit to a court of appropriate jurisdiction
the question  whether such  indemnification  by it is against  public  policy as
expressed  in the  Securities  Act of 1933 and  will be  governed  by the  final
adjudication of such issue.









                                   SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, KeySpan  Corporation
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-3 and has  duly  caused  this  registration
statement  amendment  to be signed on its behalf by the  undersigned,  thereunto
duly authorized,  in the City of Brooklyn, State of New York, on the 12th day of
April, 2001.

KEYSPAN CORPORATION
Issuer of Securities
(Registrant)

By:  /s/Gerald Luterman
Gerald Luterman
Chief Financial Officer and Senior Vice-President
(Principal Financial Officer)

Pursuant to the  requirements of the Securities Act of 1933,  this  registration
statement has been signed below by the following  persons in the  capacities and
on the dates indicated.


Signatures and Titles:                                          Date:
                                  *                             April 12, 2001
- -----------------------------------------------------------
Robert B. Catell
Chief Executive Officer and Director
(Principal Executive Officer)

  /s/Gerald Luterman                                            April 12, 2001
- -----------------------------------------------------------
Gerald Luterman
Chief Financial Officer and Senior Vice-President
(Principal Financial Officer)

  /s/Ronald Jendras                                             April 12, 2001
- -----------------------------------------------------------
Ronald Jendras
Vice President, Controller and Chief Accounting
Officer
(Principal Accounting Officer)

                                   *                            April 12, 2001
- -----------------------------------------------------------
Lilyan H. Affinito
Director
                                  *                             April 12, 2001
- -----------------------------------------------------------
Howard R. Curd
Director

                                  *                             April 12, 2001
- -----------------------------------------------------------
Richard N. Daniel
Director

                                  *                             April 12, 2001
- -----------------------------------------------------------
Donald H. Elliott
Director

                                  *                             April 12, 2001
- -----------------------------------------------------------








Alan H. Fishman
Director

                                  *                            April 12, 2001
- ----------------------------------------------------------
James R. Jones
Director

                                  *                            April 12, 2001
- ----------------------------------------------------------
Stephen W. McKessy
Director

                                  *                            April 12, 2001
- ----------------------------------------------------------
Edward D. Miller
Director

                                  *                            April 12, 2001
- ----------------------------------------------------------
James Q. Riordan
Director

   /s/Ronald Jendras                                           April 12, 2001
- ----------------------------------------------------------
Ronald Jendras, as Attorney-in-Fact
Vice President, Controller and Chief Accounting
Officer

- ----------------------

* Such  signature  has been affixed  pursuant to a power of attorney  previously
filed as an exhibit .









                                  EXHIBIT INDEX



   Exhibit Number    Description of Exhibits
   --------------    -----------------------

          5*         Opinion of Steven L.  Zelkowitz  as to the legality of the
                     common stock to be issued

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

       23-b*         Consent of Steven L. Zelkowitz (contained in his Opinion
                     filed as Exhibit 5 hereto)

       24-a**        Powers of Attorney

       24-b**        Certified resolution of the Board of Directors of KeySpan
                     Energy authorizing signatures pursuant to power of attorney


- -----------------
*Filed herewith.
**Previously filed