X0304 4 2012-02-28 1 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 2012-02-28 4 M 0 3333 29.52 A 57050 D Common Shares 2012-02-28 4 M 0 3333 32.70 A 60383 D Common Shares 2012-02-28 4 M 0 1222 61.51 A 61605 D Common Shares 2012-02-28 4 S 0 8261 66.4307 D 53344 D Common Shares 2012-02-29 4 S 0 8627 66.4345 D 44717 D Employee Stock Options (right to buy) 29.52 2012-02-28 4 M 0 3333 0.00 D 2004-12-31 2013-12-31 Common Shares 3333 0 D Employee Stock Options (right to buy) 32.70 2012-02-28 4 M 0 3333 0.00 D 2006-01-03 2015-01-03 Common Shares 3333 0 D Employee Stock Options (right to buy) 61.51 2012-02-28 4 M 0 1222 0.00 D 2012-02-22 2021-02-22 Common Shares 1222 3668 D Represents a weighted average sale price: the sales prices range from $66.40 to $66.52. Upon request, the full sale information regarding the number of shares sold at each price increment will be provided to the U.S. Securities and Exchange Commission, the issuer or a security holder of the issuer. Represents a weighted average sale price: the sales prices range from $66.40 to $66.60. Upon request, the full sale information regarding the number of shares sold at each price increment will be provided to the U.S. Securities Exchange Commission, the issuer or a security holder of the issuer. These securities vest in four equal annual installments with the first installment vesting on the date shown. /s/ Wesley D. Dupont, by Power of Attorney 2012-03-01