AHL Aspen Insurance Holdings Limited Ordinary Shares

Aspen Insurance Holdings Limited (the �Company�) (NYSE:AHL) today announced that it will enter the Professional Liability Insurance market in September 2007 through Aspen Insurance UK Limited. Underwriting will take place solely from Aspen�s UK offices and will target customers outside of the USA, principally in the UK and Australia. The underwriting focus will be on medium to larger sized customers who will value the risk management services that Aspen intends to provide. The main business will be indemnity based coverage for professional firms. The impact on Aspen�s premium development in 2007 is expected to be minimal although gross written premiums are anticipated to be in the region of $100 million within three years. The underwriting unit will be headed by Nick Evans who has 22 years of experience of successfully underwriting this class of business with a particular focus on the deployment of risk management techniques. Nick will be supported by a small group of underwriters and other professionals who will focus directly on developing this line of business for Aspen. Chris O�Kane, Chief Executive Officer of Aspen commented, �We are very excited about welcoming Nick Evans and our new colleagues. We were attracted to Nick by his strong market reputation and his thoughtful risk management led approach to underwriting which will fit extremely well with Aspen�s underwriting philosophy and accords with the diversification strategy we have pursued since the inception of our Company.� About Aspen Insurance Holdings Limited Aspen is a Bermudian holding company providing property and casualty reinsurance in the global market, property and liability insurance principally in the United Kingdom and the United States and specialty insurance and reinsurance consisting mainly of marine and energy and aviation worldwide. Aspen�s operations are conducted through its wholly-owned subsidiaries located in London, Bermuda and the United States: Aspen Insurance UK Limited, Aspen Insurance Limited and Aspen Specialty Insurance Company. Aspen has four operating segments: property reinsurance, casualty reinsurance, specialty insurance and reinsurance and property and casualty insurance. For more information about Aspen, please visit the Company�s website at www.aspen.bm. Application of the Safe Harbor of the Private Securities Litigation Reform Act of 1995 This press release contains written, and Aspen's officers may make related oral, "forward-looking statements" within the meaning of the U.S. federal securities laws regarding new lines of business and the appointment of employees. 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, estimates and data concerning future results and events and are subject to a number of uncertainties and other factors, many of which are outside Aspen's control that could cause actual results to differ materially from such statements. For a detailed description of uncertainties and other factors that could impact the forward-looking statements in this release, please see the "Risk Factors" section in Aspen's Annual Report on Form 10-K for the year ended December 31, 2006, filed with the U.S. Securities and Exchange Commission on February 22, 2007.