Dawn Zacharow Joins Allied World Europe's Growing SME Division

PEMBROKE, Bermuda, June 10, 2010 - Allied World Assurance Company Holdings, Ltd (NYSE: AWH) announced today
that Allied World Assurance Company (Europe) Limited has hired Dawn Zacharow
to join its growing SME (small to medium sized enterprises) division. Ms.
Zacharow will work out of the company's London office. She will be involved
in the underwriting of the company's Professional Indemnity products, as well
as the development of new products. Ms. Zacharow has over a decade of
experience in the insurance industry. Prior to joining Allied World, she
worked for Argo Managing Agency Limited

Kevin Cleary, Vice President, SME, Professional Lines in Europe
commented, "Dawn has a tremendous amount of technical experience in
construction-related Professional Indemnity products and I am confident she
will be a great asset to the department. She has an excellent reputation in
the market and a solid broker following and I look forward to utilising her
knowledge to continue to grow this book of business."

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, Europe, Hong Kong, Singapore and the United States. 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 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; 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.

Media, Faye Cook, VP, Marketing & Communications, +1-441-278-5406, faye.cook at awac.com; or Investors, Keith J. Lennox, Investor Relations Officer, +1-646-794-0750, keith.lennox at awac.com, both of Allied World Assurance Company Holdings, Ltd