X0303 4 2011-02-21 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001428511 Knight W. Gordon ALLIED WORLD ASSURANCE CO. HOLDINGS, AG LINDENSTRASSE 8 BAAR/ZUG V8 CH-67340 SWITZERLAND 0 1 0 0 President, AWACUS & AWNAC Common Shares 2011-02-21 4 A 0 30000 0.00 A 40060 D Common Shares 2011-02-22 4 M 0 2200 0.00 A 42260 D Common Shares 2011-02-22 4 D 0 880 62.0515 D 41380 D Common Shares 2011-02-22 4 F 0 540 61.51 D 40840 D Restricted Stock Units 2011-02-22 4 M 0 2200 D 2011-02-22 2014-02-22 Common Shares 2200 10350 D Restricted Stock Units 2011-02-22 4 A 0 2790 0.00 A Common Shares 2790 13140 D Employee Stock Options (right to buy) 61.51 2011-02-22 4 A 0 10590 0.00 A Common Shares 10590 10590 D Represents the Company's Common Shares that were earned pursuant to a 2008 LTIP award for no monetary consideration and which vested at 150% of target based on the achievement of pre-established performance criteria during the applicable three-year performance period established under the Company's Third Amended and Restated Long-Term Incentive Plan. Includes 356 Common Shares acquired on June 30, 2010 and 191 Common Shares acquired on December 31, 2010 pursuant to the Company's Amended and Restated 2008 Employee Share Purchase Plan. On February 22, 2010, the reporting person was granted 8,800 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 5,280 of the Company's Common Shares and (ii) cash equal to the market value of 3,520 Common Shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. The fair market value of the cash portion was determined using the daily volume-weighted average sales price of the Company's Common Shares for the five consecutive trading days up to and including February 22, 2011. Exclusively represents shares withheld by the Company with respect to the payment of withholding tax liability incurred upon the vesting of Restricted Stock Units. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 22, 2011. Grant of Restricted Stock Units for no monetary consideration. 2,790 Restricted Stock Units convert into (i) 1,395 of the Company's Common Shares and (ii) cash equal to the market value of 1,395 Common Shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. The Restricted Stock Units and Employee Stock Options vest in four equal installments with the first installment vesting on February 22, 2012. /s/ Wesley D. Dupont, by Power of Attorney 2011-02-22