X0304 4 2012-02-22 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001474077 Bell David ALLIED WORLD ASSURANCE CO. HOLDINGS, AG LINDENSTRASSE 8 BAAR/ZUG V8 CH-6340 SWITZERLAND 0 1 0 0 COO Common Shares 2012-02-22 4 A 0 13500 0.00 A 52794 D Common Shares 2012-02-22 4 M 0 322 0.00 A 53116 D Common Shares 2012-02-22 4 M 0 750 0.00 A 53866 D Common Shares 2012-02-22 4 D 0 461 66.8906 D 53405 D Restricted Stock Units 2012-02-22 4 M 0 322 D Common Shares 322 4468 D Restricted Stock Units 2012-02-22 4 M 0 750 D Common Shares 750 3718 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. On February 22, 2011, the reporting person was granted 1,290 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 645 of the Company's Common Shares and (ii) cash equal to the market value of 645 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 3,000 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 1,800 of the Company's Common Shares and (ii) cash equal to the market value of 1,200 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. 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. /s/ Wesley D. Dupont, by Power of Attorney 2012-02-23