Aspen Insurance Holdings Limited Announces Receipt of Demand Notice from Selling Shareholders.

HAMILTON, Bermuda -- Aspen Insurance Holdings Limited (the "Company") (NYSE:AHL) (BSX:AHL BH) received a demand notice dated March 7, 2005 from certain shareholders pursuant to the Registration Rights Agreement between Aspen and its founding shareholders relating to an underwritten offering of ordinary shares the value of which will be up to $150,000,000. Pursuant to the terms of the Agreement, Aspen intends to send notice of this demand to other founding shareholders and inform them of their right to participate in any related offering by such selling shareholders. Aspen would not sell any ordinary shares in any such offering and would not receive any proceeds from any such 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 the ordinary shares in any state 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. Any offering will be made only by means of a written prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

About Aspen Insurance Holdings Limited

Aspen Insurance Holdings Limited was established in June 2002. Aspen is a Bermudian holding company that provides property and casualty reinsurance in the global market, property and liability insurance principally in the United Kingdom and surplus lines insurance in the United States. Aspen's operations are conducted through its wholly owned subsidiaries located in London, Bermuda and the United States: Aspen Insurance UK Limited (Aspen Re), Aspen Insurance Limited (Aspen), Aspen Specialty Insurance Company (Aspen Specialty) and Aspen Re America Inc (Aspen Re America). Aspen's reinsurance segment consists of property reinsurance, casualty reinsurance and specialty reinsurance lines of business. Aspen's insurance segment consists of commercial property, commercial liability, marine and aviation, and U.S. surplus insurance lines of business. Aspen's principal existing shareholders include The Blackstone Group, Candover Partners Limited, Wellington Underwriting plc and Credit Suisse First Boston Private Equity.

Application of the Safe Harbor of the Private Securities Litigation Reform Act of 1995

This press release contains, and Aspen's earnings conference call may contain, written or oral "forward-looking statements" within the meaning of the U.S. federal securities laws. These statements are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include all statements that do not relate solely to historical or current facts, and can be identified by the use of words such as "expect," "intend," "plan," "believe," "project," "anticipate," "seek," "will," "estimate," "may," "continue," and similar expressions of a future or forward-looking nature.

All forward-looking statements rely on a number of assumptions concerning future events and are subject to a number of uncertainties and other factors, many of which are outside the Company's control that could cause actual results to differ materially from such statements. For a more detailed description of these uncertainties and other factors, please see the "Risk Factors" section in Aspen's Annual Report on Form 10-K for the year ended December 31, 2003, filed with the U.S. Securities and Exchange Commission on March 26, 2004.