X0304 4/A 2012-02-22 2012-02-23 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001473976 D'Orazio Frank ALLIED WORLD ASSURANCE CO. HOLDINGS AG LINDENSTRASSE 8 BAAR/ZUG V8 CH-6340 SWITZERLAND 0 1 0 0 Pres. Bda & Int'l Ins., AWAC Restricted Stock Units 2012-02-22 4 A 0 3120 A Common Shares 3120 7928 D Grant of Restricted Stock Units for no monetary consideration. 3,120 Restricted Stock Units convert into (i) 624 Common Shares of the Company and (ii) cash equal to the market value of 2,496 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. This Form 4/A is being filed to correct the number of Restricted Stock Units granted to the reporting person on February 22, 2012, which was reported incorrectly due to an administrative error in calculating the market value of the grant. /s/ Wesley D. Dupont, by Power of Attorney 2012-02-27