Exhibit 99.1


ILLINOVA EXTENDS ILLINOIS POWER CUMULATIVE PREFERRED
STOCK TENDER OFFER AND CONSENT SOLICITATION

HOUSTON--March 25, 2002--Illinova Corporation, a wholly owned subsidiary of
Dynegy Inc. (NYSE:DYN), today extended its offer to purchase for cash, any and
all outstanding shares of cumulative preferred stock of Illinois Power Company
(NYSE:IPC), Dynegy's transmission and distribution subsidiary, from the prior
expiration date of 12:00 midnight, New York City time on Friday, March 22, 2002
to 5:00 p.m. New York City time on Tuesday, March 26, 2002.

      Illinois Power also extended its related consent solicitation from the
prior expiration date of 12:00 midnight, New York City time on Friday, March 22,
2002 to 5:00 p.m. New York City time on Tuesday, March 26, 2002. The rights to
withdraw shares tendered and to revoke consents granted have also been extended.
The terms of the extended offer and solicitation remain unchanged from the
original offer and solicitation as set forth in the offering materials. Payment
for all validly tendered and/or consented and accepted shares is expected to be
made on or about March 28, 2002.

      Based on a preliminary count by Mellon Investor Services, L.L.C., the
depositary and information agent for the tender offer and consent solicitation,
Illinova Corporation and IPC expect to successfully close the tender offer and
consent solicitation on March 26, 2002. According to Mellon Investor Services,
L.L.C.'s preliminary count, as of 12:00 midnight, Friday, March 22, 2002, in
aggregate, 72% of the holders of record consented and the following number of
shares of IPC's cumulative preferred stock tendered and not withdrawn was as
follows:

                                                              Shares
             Series                      CUSIP No.           Tendered
--------------------------------        -----------          --------
4.08% Cumulative Preferred Stock        452092-20-8           132,911
4.20% Cumulative Preferred Stock        452092-30-7            94,145
4.26% Cumulative Preferred Stock        452092-40-6            70,362
4.42% Cumulative Preferred Stock        452092-50-5            69,109
4.70% Cumulative Preferred Stock        452092-60-4           107,528
7.75% Cumulative Preferred Stock        452092-79-4           182,681


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CONTACT:
     Dynegy Inc., Houston
     Media:
     John Sousa, Steve Stengel or Claudia Morlan, 713/767-5800
     or
     Analysts:
     Arthur Shannon or Katie Pipkin, 713/507-6466