Exhibit 99.1

DYNEGY BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS

STOCKHOLDERS TENDER SHARES INTO THE ICAHN TENDER OFFER

HOUSTON, December 30, 2010 – Dynegy Inc. (NYSE: DYN) today announced that its Board of Directors, in consultation with its independent financial and legal advisors, has unanimously determined that the tender offer commenced by an affiliate of Icahn Enterprises LP (NYSE: IEP) on December 22, 2010, is in the best interests of all Dynegy stockholders and unanimously recommends that Dynegy stockholders accept the tender offer and tender their Dynegy shares into the tender offer. Dynegy has filed with the Securities and Exchange Commission (“SEC”) a Solicitation/Recommendation Statement on Schedule 14D-9 regarding the tender offer.

Dynegy is soliciting superior proposals from potentially interested parties, and is permitted under the terms of its agreement with IEP to continue to do so until 11:59 p.m. (Eastern Time) on January 24, 2011. Dynegy invites interested third parties to contact its financial advisors. It is not anticipated that any developments will be disclosed with regard to this process unless the Dynegy Board of Directors makes a decision with respect to any potential superior proposal, and there are no guarantees that this process will result in a superior proposal. IEP has agreed that, in certain circumstances, if a “superior” all cash offer is made and supported by Dynegy, and IEP does not wish to top the “superior” offer, it will support it.

The IEP tender offer is currently set to expire at midnight (Eastern Time) on January 25, 2011.

Shareholders are encouraged to read the Schedule 14D-9 filing, which is available on the SEC’s website, www.sec.gov. In addition, the Schedule 14D-9 filing, this press release and other materials related to the Icahn Enterprises LP offer are available in the “Investor Relations” section of Dynegy’s website at www.dynegy.com.

Goldman, Sachs & Co. and Greenhill & Co., LLC are serving as financial advisors and Sullivan & Cromwell LLP is serving as legal counsel to Dynegy.

About Dynegy Inc.

Through its subsidiaries, Dynegy Inc. produces and sells electric energy capacity and ancillary services in key U.S. markets. The power generation portfolio consists of approximately 12,100 megawatts of baseload, intermediate and peaking power plants fueled by a mix of natural gas, coal and fuel oil. For more information, please visit www.dynegy.com.

Cautionary Statement Regarding Forward-Looking Statements

This press release contains statements reflecting assumptions, expectations, projections, intentions or beliefs about future events that are intended as “forward looking statements.” Discussion of risks and uncertainties that could cause actual results to differ materially from current projections, forecasts, estimates and expectations of Dynegy is contained in Dynegy’s filings with the Securities and Exchange Commission (the “SEC”). Specifically, Dynegy makes reference to, and incorporates herein by reference, the section entitled “Risk Factors” in its most recent Form 10-K and subsequent reports on Form 10-Q, the section entitled “Cautionary Statement Regarding Forward-Looking Statements” in its definitive proxy statement filed with the SEC on October 4, 2010 and the section entitled “Forward-Looking Statements” in its preliminary consent revocation statement filed with the SEC on November 26, 2010. In addition to the risks and uncertainties set forth in Dynegy’s SEC filings, the forward-looking statements described in this press release could be affected by, among other things, (i) the timing and anticipated benefits to be achieved through Dynegy’s 2010-2013 company-wide cost savings program; (ii) beliefs and assumptions relating to liquidity, available borrowing capacity and capital resources generally; (iii)

expectations regarding environmental matters, including costs of compliance, availability and adequacy of emission credits, and the impact of ongoing proceedings and potential regulations or changes to current regulations, including those relating to climate change, air emissions, cooling water intake structures, coal combustion byproducts, and other laws and regulations to which Dynegy is, or could become, subject; (iv) beliefs about commodity pricing and generation volumes; (v) anticipated liquidity in the regional power and fuel markets in which Dynegy transacts, including the extent to which such liquidity could be affected by poor economic and financial market conditions or new regulations and any resulting impacts on financial institutions and other current and potential counterparties; (vi) sufficiency of, access to and costs associated with coal, fuel oil and natural gas inventories and transportation thereof; (vii) beliefs and assumptions about market competition, generation capacity and regional supply and demand characteristics of the wholesale power generation market, including the potential for a market recovery over the longer term; (viii) the effectiveness of Dynegy’s strategies to capture opportunities presented by changes in commodity prices and to manage its exposure to energy price volatility; (ix) beliefs and assumptions about weather and general economic conditions; (x) beliefs regarding the U.S. economy, its trajectory and its impacts, as well as Dynegy’s stock price; (xi) projected operating or financial results, including anticipated cash flows from operations, revenues and profitability; (xii) expectations regarding Dynegy’s revolver capacity, credit facility compliance, collateral demands, capital expenditures, interest expense and other payments; (xiii) Dynegy’s focus on safety and its ability to efficiently operate its assets so as to maximize its revenue generating opportunities and operating margins; (xiv) beliefs about the outcome of legal, regulatory, administrative and legislative matters; (xv) expectations and estimates regarding capital and maintenance expenditures, including the Midwest Consent Decree and its associated costs; (xvi) uncertainties associated with the consent solicitation (the “Seneca Capital Solicitation”) engaged in by Seneca Capital International Master Fund, L.P., Seneca Capital, L.P., Seneca Capital Investments, L.P., Seneca Capital Investments, LLC, Seneca Capital International GP, LLC, Seneca Capital Advisors, LLC and Douglas A. Hirsch (“Seneca Capital”) and (xvii) uncertainties associated with the proposed acquisition of Dynegy by an affiliate of Icahn Enterprises LP (the “Transaction”), including uncertainties relating to the anticipated timing of filings and approvals relating to the Transaction, the outcome of legal proceedings that may be instituted against Dynegy and/or others relating to the Transaction, the expected timing of completion of the Transaction, the satisfaction of the conditions to the consummation of the Transaction and the ability to complete the Transaction. Any or all of Dynegy’s forward-looking statements may turn out to be wrong. They can be affected by inaccurate assumptions or by known or unknown risks, uncertainties and other factors, many of which are beyond Dynegy’s control.

Notice to Investors

This press release is neither an offer to purchase nor a solicitation of an offer to sell any securities. The solicitation and the offer to buy the outstanding shares of common stock of Dynegy Inc. (the “Company”) are being made pursuant to an offer to purchase and related materials that IEH Merger Sub LLC (the “Offeror”), an affiliate of Icahn Enterprises LP, has filed with the SEC. The Offeror has filed a tender offer statement on Schedule TO with the SEC in connection with the commencement of the offer, and the Company has filed a solicitation/recommendation statement on Schedule 14D-9 with respect to the offer. The tender offer statement (including an offer to purchase, a related letter of transmittal and other offer documents) and the solicitation/recommendation statement contain important information that should be read carefully and considered before any decision is made with respect to the tender offer. These materials have or will be sent free of charge to all stockholders of the Company. In addition, all of these materials (and all other materials filed by the Company with the SEC) are or will be available at no charge from the SEC through its website at www.sec.gov. The Schedule 14D-9 and related materials may be obtained for free from D.F. King & Co., Inc., Toll-Free Telephone: (800) 697-6975. Investors may also obtain copies of the Schedule TO and the related materials free from Morrow & Company; banks and brokerage firms can call Morrow & Company at (203) 657-9400, and stockholders can call Morrow & Company toll free at (800) 607-0088 . Investors and security holders may also obtain free copies of the

documents filed with the SEC by the Company by directing a request by mail or telephone to Dynegy Inc., Attn: Corporate Secretary, 1000 Louisiana Street, Suite 5800, Houston, Texas 77002, telephone: (713) 507-6400, or from Dynegy’s website, http://www.dynegy.com.

Additional Information About the Merger and Where to Find It

In connection with the potential merger, the Company will prepare a proxy statement to be filed with the SEC. When completed, a definitive proxy statement and a form of proxy will be mailed to the stockholders of the Company. BEFORE MAKING ANY VOTING DECISION, THE COMPANY’S STOCKHOLDERS ARE URGED TO READ THE PROXY STATEMENT REGARDING THE MERGER CAREFULLY AND IN ITS ENTIRETY BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED MERGER. The Company’s stockholders will be able to obtain, without charge, a copy of the proxy statement (when available) and other relevant documents filed with the SEC from the SEC’s website at http://www.sec.gov. The Company’s stockholders will also be able to obtain, without charge, a copy of the proxy statement and other relevant documents (when available) by directing a request by mail or telephone to Dynegy Inc., Attn: Corporate Secretary, 1000 Louisiana Street, Suite 5800, Houston, Texas 77002, telephone: (713) 507-6400, or from the Company’s website, http://www.dynegy.com.

Participants in the Solicitation

Dynegy and its directors and officers may be deemed to be participants in the solicitation of proxies from Dynegy’s stockholders with respect to the Merger. Information about Dynegy’s directors and executive officers and their ownership of Dynegy’s common stock is set forth in the proxy statement for Dynegy’s 2010 Annual Meeting of Stockholders, which was filed with the SEC on April 2, 2010. Stockholders may obtain additional information regarding the interests of the Company and its directors and executive officers in the Merger, which may be different than those of the Company’s stockholders generally, by reading the proxy statement and other relevant documents regarding the Merger, when filed with the SEC.

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