Celanese Announces Commencement of Stockholder Offering

Celanese Corporation (NYSE: CE) (the “Company”) announced today that it was informed that Blackstone Capital Partners (Cayman) Ltd. 1, Blackstone Capital Partners (Cayman) Ltd. 2, Blackstone Capital Partners (Cayman) Ltd. 3 and Blackstone Management Partners IV L.L.C. had commenced a registered public secondary offering of 22,106,597 shares of the Company’s Series A common stock pursuant to the Company’s universal shelf registration statement filed on May 9, 2006. Upon completion of this offering, funds affiliated with The Blackstone Group, L.P. will no longer own any shares of common stock of the Company. The Company will not receive any of the proceeds from this offering.

Morgan Stanley is acting as the sole underwriter for the offering.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.

A prospectus supplement relating to the offering will be filed with the Securities and Exchange Commission. When available, copies of the prospectus supplement and the accompanying base prospectus may be obtained by contacting Morgan Stanley & Co. Incorporated, Prospectus Department, 180 Varick Street, 2nd Floor, New York, NY 10014, 866-718-1649, or by e-mail at prospectus@morganstanley.com.

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