AGNC Added to Preliminary List of Russell 3000

June 25, 2008

BETHESDA, Md., June 25 /PRNewswire-FirstCall/ -- American Capital Agency Corp. (Nasdaq: AGNC), a real estate investment trust (REIT) formed in 2008 and externally managed by an affiliate of American Capital Strategies, Ltd. (Nasdaq: ACAS) (American Capital), announced today that Russell Investments has included AGNC in its preliminary list of companies slated to join the Russell 3000 Index at the close of the market on Friday, June 27, 2008, when Russell reconstitutes its family of indexes for 2008. Final index membership will be posted by Russell on Monday, June 30, 2008. The Russell 3000 Index measures the performance of the 3,000 largest public companies listed on U.S. stock exchanges, based on total market capitalization, which represents approximately 98% of the investable U.S. equity market, according to Russell. More detailed information can be found on the website of Russell Investments at www.russell.com.

We are pleased to be included in the Russell 3000 Index, following our initial public offering just last month, said John Erickson, Chief Financial Officer. We believe our inclusion in the Index will attract a wider investor audience.

AGNC recently announced a $0.31 per share dividend for the shortened stub period from the closing of its initial public offering (IPO) on May 20, 2008 through June 30, 2008. AGNC has invested approximately $2.5 billion in agency securities since the IPO and expects to have held this portfolio for an average of 27 days during the stub period.

ABOUT AGNC

AGNC is a REIT formed in 2008 to invest exclusively in agency pass-through securities and collateralized mortgage obligations for which the principal and interest payments are guaranteed by a U.S. Government agency or a U.S. Government-sponsored entity.

ABOUT AMERICAN CAPITAL

With $21 billion in capital resources under management(1), American Capital is the only private equity fund and alternative asset management company in the S&P 500. American Capital, both directly and through its global asset management business, is an investor in management and employee buyouts, private equity buyouts and early stage and mature private and public companies. American Capital provides senior debt, mezzanine debt and equity to fund growth, acquisitions, recapitalizations and securitizations. American Capital and its affiliates invest from $5 million to $800 million per company in North America and 5 million euros to 500 million euros per company in Europe.

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements. Forward-looking statements are not guarantees of future performance and are subject to various factors and uncertainties in predicting future results and conditions, including changes in interest rates, changes in the yield curve, changes in prepayment rates, the availability and terms of financing, changes in the market value of our assets, general economic conditions and market conditions.

Persons considering an investment in AGNC should consider the investment objectives, risks and charges and expenses of AGNC carefully before investing. Such information and other information about AGNC is available in AGNC's Registration Statement on Form S-11 filed with the Securities and Exchange Commission. Copies are available on the SEC's website, www.sec.gov. Prospective investors should read such material carefully before investing. The links to third-party websites referenced herein are furnished for informational purposes only. They should not be considered as endorsements or recommendations. Neither AGNC nor any of its affiliates has control over or is affiliated with such third-party websites, and does not take responsibility for their suitability or quality.

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(1) Capital resources under management is an estimate of internally and externally managed assets and available capital resources as of May 31, 2008 and does not include any fair value adjustments subsequent to March 31, 2008.

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SOURCE American Capital Agency Corp.

CONTACT:
John Erickson, Chief Financial Officer
or Tom McHale, Senior Vice President, Finance
or Justin Cressall, Vice President, Equity Capital Markets, all of American Capital
+1-301-968-9300, Fax +1-301-968-9301
Web site: http://www.AGNC.com
http://www.americancapital.com