Allied World Europe Appoints Magnus McGurk Business Development Manager

ZUG, Switzerland, May 17, 2011 - Allied World Assurance Company Holdings, AG (NYSE: AWH) announced today
that Magnus McGurk has joined Allied World Europe as Business Development
Manager (Scotland) for SME Professional Lines. Mr. McGurk will be based in
Scotland and will oversee business development and marketing in the Scotland
and Northern Irish United Kingdom market.

Frank D'Orazio, President, Bermuda & International Insurance, commented,
"We are very pleased that Magnus has joined our European team. His industry
knowledge and extensive contacts throughout Scotland and Northern Ireland
will be a great asset to the company. We look forward to expanding the
current book of business regionally."

Mr. McGurk has over a decade of experience in the Professional Lines
insurance industry. Prior to joining Allied World, he was most recently Chubb
Specialty Insurance Manager for Scotland at Chubb Insurance Company of Europe
where he focused exclusively on the Scotland region for Professional Lines.
Mr. McGurk has a degree in Risk Management from Glasgow Caledonian
University.

About Allied World Assurance Company

Allied World Assurance Company Holdings, AG, through its subsidiaries, is
a global provider of innovative property, casualty and specialty insurance
and reinsurance solutions, offering superior client service through a global
network of branches and affiliates. Our insurance and reinsurance
subsidiaries are rated A (Excellent) by A.M. Best Company, and our Lloyd's
Syndicate 2232 is rated A+ (Strong) by Standard & Poor's and Fitch. Please
visit our website at www.awac.com for further information on Allied
World.

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; 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.

Faye Cook, VP, Marketing & Communications, +1-441-278-5406, faye.cook at awac.com, or Keith J. Lennox, Investor Relations Officer, +1-646-794-0750, keith.lennox at awac.com