Prospectus Supplement Filing Under
Dated: December 6, 1999 Rules 424(b)(3) and 424(c)
To Prospectus dated May 27, 1998 Registration File No. 333-53657
KEYSPAN CORPORATION
INVESTOR PROGRAM
Effective December 6, 1999, KeySpan Corporation has changed its stock
transfer agent from The Bank of New York to EquiServe Trust Company, N.A. As of
such date, the new Plan Administrator for the KeySpan Corporation Investor
Program is now EquiServe Trust Company, N.A.
In terms of the Prospectus, dated May 27, 1998, relating to the Investor
Program:
- References to the transfer agent are changed to read EquiServe Trust
Company, N.A.
- References to the "Plan Administrator" should be read to mean
EquiServe Trust Company, N.A. rather than The Bank of New York.
- References to "BNY ESI & Co. as a full-service brokerage firm," are
omitted and the following language included: "EquiServe may, in its
sole discretion, use a broker-dealer affiliated with EquiServe to
execute purchase or sale transactions. In that event, the Participant
should recognize that brokerage commissions assessed in connection
with those transactions will be paid to EquiServe's affiliate."
- References to corresponding with the Plan Administrator should read to
direct correspondence to: Shareholder Inquiries, EquiServe Trust
Company, N.A., P.O. Box 2598, Jersey City, NJ 07303-2598.
- References to the Plan Administrator's Internet address should read
as: http://www.equiserve.com.
- References to investments should read to make optional cash investment
checks payable to: Investment Plan Services, EquiServe Trust Company,
N.A., P.O. Box 13531, Newark, N.J. 07188-0001.
- References to sales should read to make sales requests by calling
1-800-482-3638, or by written request mailed to: EquiServe Trust
Company, N.A., P.O. Box 2598, Newark, N.J. 07303-2598.
Prospective shareholders requesting Program material should call
1-800-948-1691. Any questions regarding the KeySpan Corporation Investor Program
should be directed to a KeySpan representative at 1-800-482-3638.
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This Prospectus Supplement should be affixed to your
copy of the prospectus dated May 27, 1998.
