Allied World Appoints Katherine Richardson Senior Vice President, Human Resources

PEMBROKE, Bermuda - Allied World Assurance Company Holdings, Ltd (NYSE: AWH) today announced that Katherine Richardson has joined Allied World National Assurance Company as Senior Vice President, Human Resources, responsible for HR functions globally. Ms. Richardson is a senior HR leader with 15 years of generalist management experience in the financial services and insurance industries.

Scott Carmilani, President and Chief Executive Officer of Allied World, commented, “Katherine’s experience in the industry demonstrates her ability to lead HR strategy and execution in times of great change and challenge. We are pleased to have Katherine join the Allied World team and look forward to her contributions to the leadership and talent development of our global operations. Her knowledge and enthusiasm will be a great asset to our company.”

Previous to her position with Allied World, Ms. Richardson spent ten years in Human Resources roles at AIG. Most recently, she supported clients in AIG’s Corporate Center, including the Corporate Financial Groups, Internal Audit and AIG’s Restructuring office, in addition to six years in domestic commercial insurance operations in Boston, New York and Atlanta. Ms. Richardson graduated magna cum laude from Texas A&M University with a Bachelor of Arts degree in Business and History, through the Program 5 honors program.

About Allied World Assurance Company

Allied World Assurance Company Holdings, Ltd, through its subsidiaries, is a global provider of innovative property, casualty and specialty insurance and reinsurance solutions, offering superior client service through offices in Bermuda, the United States, Europe and Hong Kong. Our insurance and reinsurance subsidiaries are rated A (Excellent) by A.M. Best Company. For further information on Allied World, please visit our website at www.awac.com.

Cautionary Statement Regarding Forward-Looking Statements

Any forward-looking statements made in this press release reflect our current views with respect to future events and financial performance and are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Such statements involve risks and uncertainties, which may cause actual results to differ materially from those set forth in these statements. For example, our forward-looking statements could be affected by the ability to recognize the benefits of the Darwin Professional Underwriters, Inc. acquisition; pricing and policy term trends; increased competition; the impact of acts of terrorism and acts of war; greater frequency or severity of unpredictable catastrophic events; investigations of market practices and related settlement terms; negative rating agency actions; the adequacy of our loss reserves; the company or its subsidiaries becoming subject to significant income taxes in the United States or elsewhere; changes in regulations or tax laws; changes in the availability, cost or quality of reinsurance or retrocessional coverage; adverse general economic conditions including those related to the ongoing financial crisis; and judicial, legislative, political and other governmental developments, as well as management’s response to these factors, and other factors identified in our filings with the U.S. Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date on which they are made. We are under no obligation (and expressly disclaim any such obligation) to update or revise any forward-looking statement that may be made from time to time, whether as a result of new information, future developments or otherwise.

Source: Allied World Assurance Company Holdings, Ltd

Faye Cook, VP, Marketing & Communications, +1-646-794-0543, Faye.cook at awac.com, or Keith Lennox, Investor Relations Officer, +1-646-794-0750, keith.lennox at awac.com, both of Allied World Assurance Company Holdings