X0304 4 2012-02-22 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001368443 Carmilani Scott A ALLIED WORLD ASSURANCE CO. HOLDINGS, AG LINDENSTRASSE 8 BAAR/ZUG V8 CH-6340 SWITZERLAND 1 1 0 0 President, CEO and Chairman Common Shares 2012-02-22 4 A 0 147408 0.00 A 447976 D Common Shares 2012-02-22 4 M 0 2954 0.00 A 450930 D Common Shares 2012-02-22 4 M 0 3250 0.00 A 454180 D Common Shares 2012-02-22 4 D 0 2777 66.8906 D 451403 D Common Shares 2012-02-22 4 F 0 70446 66.88 D 380957 D Restricted Stock Units 2012-02-22 4 M 0 2954 D Common Shares 2954 23616 D Restricted Stock Units 2012-02-22 4 M 0 3250 D Common Shares 3250 20366 D Restricted Stock Units 2012-02-22 4 A 0 22667 A Common Shares 22667 43033 D Represents the Company's Common Shares that were earned pursuant to performance-based awards granted in 2008 and 2009 for no monetary consideration and which vested at 150% of target based on the achievement of pre-established performance criteria during the applicable performance period established under the Company's Third Amended and Restated Long-Term Incentive Plan. On February 22, 2011, the reporting person was granted 11,820 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 5,910 of the Company's Common Shares and (ii) cash equal to the market value of 5,910 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 13,000 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 7,800 of the Company's Common Shares and (ii) cash equal to the market value of 5,200 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. 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. 22,667 Restricted Stock Units convert into (i) 4,533 Common Shares of the Company and (ii) cash equal to the market value of 18,134 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