Allied World Announces Completion of Redomestication of Holding Company from Bermuda to Switzerland

PEMBROKE, Bermuda, December 1, 2010 - Allied World Assurance Company Holdings, AG (NYSE: AWH) announced today
that it has completed the previously announced redomestication of its group
holding company from Bermuda to Switzerland. The new Swiss holding company
will remain subject to the U.S. Securities and Exchange Commission reporting
requirements, the applicable corporate governance rules of the New York Stock
Exchange (NYSE) and will continue to report its consolidated financial
results in U.S. dollars and under U.S. generally accepted accounting
principles. Shareholders will continue to receive dividends in U.S. dollars,
and the company's common shares will continue to trade on the NYSE under the
ticker symbol "AWH."

On November 18, 2010, Allied World's shareholders approved the proposed
scheme of arrangement related to the company's redomestication to
Switzerland. The redomestication became official following the filing of the
Supreme Court of Bermuda's approval of the scheme of arrangement with the
Bermuda Registrar of Companies.

Scott Carmilani, Allied World's President and Chief Executive Officer,
said "We are very excited about our redomestication to Switzerland. We have
grown from a Bermuda based start-up in 2001 to a global organization with
over 700 employees located in eight different countries. We see this
redomestication as a strategic step in our company's progression as we move
forward with the goal of enhancing our presence around the world."

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 difficulties we may encounter with the transition to a
new jurisdiction of incorporation and statutory regime; 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.

Media: Faye Cook, Vice President, 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