Allied World Schedules First Quarter 2011 Earnings Announcement and Conference Call

ZUG, Switzerland, April 12, 2011 - Allied World Assurance Company Holdings, AG (NYSE: AWH) today announced
that it will release its financial results for the first quarter ended March
31, 2011, after the close of market on Wednesday, May 4, 2011.

Scott Carmilani, President and Chief Executive Officer, and Joan Dillard,
Chief Financial Officer, will host a conference call on Thursday, May 5, 2011
at 9:00 am (Eastern Time) to discuss the first quarter 2011 financial
results. This call will include a question and answer session.

The conference call can be accessed by dialing +1-877-317-6701 (U.S. and
Canada callers) or +1-412-317-6701 (international callers) and entering the
passcode 4757432 approximately ten minutes prior to the call. A live webcast
of the call will be available online at www.awac.com. A replay of the
call will be available through Thursday, May 19, 2011 by dialing
+1-877-344-7529 (U.S. and Canada callers) or +1-412-317-0088 (international
callers) and entering the passcode 449870. In addition, the webcast will
remain available online through Thursday, May 19, 2011 at www.awac.com.

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