Allied World Asia Launches Environmental Liability

ZUG, Switzerland, March 16, 2011 - Allied World Assurance Company Holdings, AG (NYSE: AWH) announced today
that Allied World Assurance Company Ltd. has launched an environmental
liability line of business that will focus on risks throughout the
Asia-Pacific region. Jota Shohtoku, Vice President, Head of General Casualty
(Asia-Pacific) for Allied World, is based in Hong Kong and will be
responsible for overseeing the development of this new line of business, in
addition to managing the General Casualty portfolio in the region.

The initial product offerings include both Contractors Pollution
Liability and Pollution Liability for scheduled sites. Policy wordings will
be custom tailored to meet clients' geographical and operational needs, and
coverage is designed to complement clients' current General Liability and/or
Public Liability programs that are also offered by Allied World's platform in
the Asia-Pacific region. Limits offered will be up to $10mm(USD) for each
pollution incident and in the aggregate.

Mr. Shohtoku commented, "We created this line of business in response to
our clients' needs. Businesses throughout the region are now required to have
environmental liability insurance either through regulation or contractual
obligation and we recognize the value in providing this service." Mr.
Shohtoku brings a decade of environmental insurance underwriting and
management experience to Allied World. Prior to joining Allied World, he held
various positions in the environmental insurance industry; most recently
launching Chartis Insurance's environmental liability platform in Asia. Mr.
Shohtoku holds a Masters Degree in Environmental Science and Management from
the University of California, Santa Barbara, and a Bachelor's Degree in Civil
and Environmental Engineering from the University of Edinburgh.

For more information, please contact Mr. Shohtoku at
jota.shohtoku@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
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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