X0303 4 2011-02-22 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001456268 Gauthier John J ALLIED WORLD ASSURANCE CO. HOLDINGS, AG LINDENSTRASSE 8 BAAR/ZUG V8 CH-6340 SWITZERLAND 0 1 0 0 EVP & CIO, Newmarket Admin Common Shares 2011-02-22 4 M 0 1100 0.00 A 6516 D Common Shares 2011-02-22 4 D 0 440 62.0515 D 6076 D Common Shares 2011-02-22 4 F 0 236 61.51 D 5840 D Restricted Stock Units 2011-02-22 4 M 0 1100 D 2011-02-22 2014-02-22 Common Shares 1100 5550 D Restricted Stock Units 2011-02-22 4 A 0 1220 0.00 A Common Shares 1220 6770 D Employee Stock Option (right to buy) 61.51 2011-02-22 4 A 0 4620 0.00 A Common Shares 4620 4620 D On February 22, 2010, the reporting person was granted 4,400 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 2,640 of the Company's Common Shares and (ii) cash equal to the market value of 1,760 Common Shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. Includes 198 Common Shares acquired on December 31, 2010 pursuant to the Company's Amended and Restated 2008 Employee Share Purchase Plan. 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 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. 1,220 Restricted Stock Units convert into (i) 610 of the Company's Common Shares and (ii) cash equal to the market value of 610 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