X0304 4 2012-02-22 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, AWAC ServCo. Common Shares 2012-02-22 4 A 0 8438 0.00 A 14631 D Common Shares 2012-02-22 4 M 0 304 0.00 A 14935 D Common Shares 2012-02-22 4 M 0 1100 0.00 A 16035 D Common Shares 2012-02-22 4 D 0 592 66.8906 D 15443 D Common Shares 2012-02-22 4 F 0 3186 66.88 D 12257 D Resticted Stock Units 2012-02-22 4 M 0 304 D Common Shares 304 5716 D Restricted Stock Unis 2012-02-22 4 M 0 1100 D Common Shares 1100 4616 D Restricted Stock Units 2012-02-22 4 A 0 2345 A Common Shares 2345 6961 D Represents the Company's Common Shares that were earned pursuant to a 2009 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 187 Common Shares acquired on December 31, 2011 pursuant to the Company's Amended and Restated 2008 Employee Share Purchase Plan. On February 22, 2011, the reporting person was granted 1,220 Restricted Stock Units for no monetary consideration. The 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. 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. 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, 2012. Exclusively represents shares withheld by the Company with respect to the payment of withholding tax liability incurred upon the vesting of performance-based awards and/or Restricted Stock Units. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 22, 2012. 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. 2,345 Restricted Stock Units convert into (i) 469 Common Shares of the Company and (ii) cash equal to the market value of 1,876 Common Shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 22, 2013. /s/ Wesley D. Dupont, by Power of Attorney 2012-02-24