Exhibit 99.1

Dynegy Announces Termination of Exchange Offers

HOUSTON, TX November 3, 2011 — Dynegy Inc. (Dynegy) (NYSE: DYN) announced today that it has terminated the previously announced offers to exchange (the Exchange Offers) up to $1,250,000,000 principal amount of the outstanding notes, debentures and capital income securities (the Old Notes) of Dynegy Holdings, LLC (DH), its direct, wholly-owned subsidiary, for Dynegy’s new 10% Senior Secured Notes due 2018 (the New Notes) and cash.

As a result of the termination, all of the previously tendered (and not validly withdrawn) Old Notes will not be accepted for exchange and will be promptly returned to the holders thereof. Neither the early tender payment nor the exchange payment will be paid to holders who have tendered their Old Notes.

This press release is neither an offer to purchase, nor a solicitation for acceptance of an offer to purchase, nor a solicitation of consents with respect to, any securities. The Exchange Offers were made only by and pursuant to the terms of the Offering Circular dated September 15, 2011 and the accompanying Letter of Transmittal.

ABOUT DYNEGY

Dynegy’s subsidiaries produce and sell electric energy, capacity and ancillary services in key U.S. markets. The Dynegy Power, LLC power generation portfolio consists of approximately 6,771 megawatts of primarily natural gas-fired intermediate and peaking power generation facilities. The Dynegy Midwest Generation, LLC portfolio consists of approximately 3,132 megawatts of primarily coal-fired baseload power plants. A separate portfolio consists of approximately 1,693 megawatts from two power plants which are primarily natural gas-fired peaking and baseload coal generation facilities.

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,” particularly those statements concerning the Exchange Offers. 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. 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) Dynegy’s ability to address its substantial leverage on favorable terms and its ability to access the capital markets when needed; (ii) the ability of management to execute any

new or revised business plan approved by Dynegy’s Board of Directors; (iii) the timing and anticipated benefits to be achieved through Dynegy’s restructuring activities and cost savings program; (iv) beliefs and assumptions relating to liquidity, available borrowing capacity and capital resources generally; (v) 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; (vi) beliefs about commodity pricing and generation volumes; (vii) 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; (viii) sufficiency of, access to and costs associated with coal, fuel oil and natural gas inventories and transportation thereof; (ix) 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; (x) the effectiveness of Dynegy’s strategies to capture opportunities presented by changes in commodity prices and to manage its exposure to energy price volatility; (xi) beliefs and assumptions about weather and general economic conditions; (xii) beliefs regarding the U.S. economy, its trajectory and its impacts, as well as Dynegy’s stock price; (xiii) expectations regarding Dynegy’s collateral demands, interest expense and other payments; (xiv) Dynegy’s focus on safety and its ability to efficiently operate its assets so as to maximize its revenue generating opportunities and operating margins; (xv) beliefs about the outcome of legal, regulatory, administrative and legislative matters; and (xvi) expectations and estimates regarding capital and maintenance expenditures, including the Midwest Consent Decree and its associated costs. 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.

Contact:

Dynegy Inc.
Media: 713-767-5800
or
Analysts: 713-507-6466

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