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                                                                    EXHIBIT 99.1

Press Release                                                Source: Dynegy Inc.

Illinois Power Announces $550 Million Mortgage Bond Offering
Tuesday December 17, 5:39 pm ET

HOUSTON--(BUSINESS WIRE)--Dec. 17, 2002--Dynegy Inc. (NYSE:DYN - News) today
announced that its subsidiary, Illinois Power Company, a regulated energy
delivery company located in Decatur, Ill., has agreed to sell $550 million of
11.5 percent mortgage bonds due 2010 in a private offering, $150 million of
which will be issued on a delayed basis subject to regulatory approval. The
mortgage bonds will be sold at a discounted price of $97.48.

Following the completion of the offering, Illinois Power will use the net
proceeds to refinance or repay debt. Closing of $400 million of mortgage bonds
is expected to occur on Dec. 20, 2002 and is subject to satisfaction of
customary closing conditions. The remaining $150 million of mortgage bonds is
expected to close, subject to approval from the Illinois Commerce Commission, in
January 2003.

"This bond offering is another important step in our efforts to improve our
financial profile. The response we received on the offering demonstrates that
the capital markets recognize the value in a new Dynegy," said Bruce A.
Williamson, president and chief executive officer of Dynegy Inc. "The expected
net proceeds will be used to repay a substantial portion of Illinois Power's
2003 debt maturities, which is consistent with our plan for Illinois Power to
meet its financing needs independently."

These mortgage bonds may be resold by the initial purchasers to certain
qualified institutional buyers pursuant to Rule 144A under the Securities Act of
1933, as amended. These mortgage bonds have not been registered under the
Securities Act and may not be offered or sold in the United States absent
registration or an applicable exemption from registration under the Securities
Act.

This news release does not constitute an offer to sell or the solicitation of an
offer to buy any security and shall not constitute an offer, solicitation or
sale in any jurisdiction in which such offering would be unlawful.

Illinois Power serves more than 650,000 natural gas and electricity customers in
a 15,000-square-mile area across Illinois.

Dynegy Inc. owns operating divisions engaged in power generation, natural gas
liquids, regulated energy delivery and communications. Through these business
units, the company serves customers by delivering value-added solutions to meet
their energy and communications needs. The company's website is www.dynegy.com.

This news release contains forward-looking statements regarding Illinois Power's
ability to complete this private placement and to use the proceeds as described.
These forward-looking statements involve a number of risks and uncertainties.
Among the important factors that could cause actual results to differ materially
from those indicated in such forward-looking statements include uncertainties
relating to market conditions for corporate debt securities in general and
Illinois Power's securities in particular, as well as the receipt of required
regulatory approvals. While we may elect to update forward-looking statements at
some point in the future, we specifically disclaim any obligation to do so.


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Contact:
     Dynegy Inc., Houston
     Media:
     John Sousa or David Byford, 713/767-5800

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     or
     Analysts:
     Katie Pipkin or Christina Cavarretta, 713/507-6466


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Source: Dynegy Inc.