X0306 4 2015-02-25 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001584980 Ziegler Kent W ALLIED WORLD ASSURANCE CO. HOLDINGS, AG GUBELSTRASSE 24, PARK TOWER, 15TH FLOOR ZUG V8 6300 SWITZERLAND 0 1 0 0 SVP, Finance & CAO Common Shares 2015-02-25 4 M 0 855 0.00 A 1207 D Common Shares 2015-02-25 4 D 0 855 40.4554 D 352 D Restricted Stock Units 2015-02-25 4 M 0 855 D Common Shares 855 8727 D On February 25, 2013, the reporting person was granted 3,423 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into cash equal to the market value of 3,423 common shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. These Restricted Stock Units were previously reported as a grant of 1,141 Restricted Stock Units that convert into cash equal to the market value of 1,141 common shares. The amount has been adjusted to reflect the issuer's 3-for-1 stock split paid on May 23, 2014. The fair market value was determined using the daily volume-weighted average sales price of the common shares for the five consecutive trading days up to and including February 25, 2015. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 25, 2014. Represents all Restricted Stock Units held by the reporting person that vest in whole or in part in cash. /s/ Wayne H. Datz, by Power of Attorney 2015-02-27