X0306 4 2016-12-09 0 0000929008 WESCO INTERNATIONAL INC WCC 0001023582 OBRIEN JAMES J /KY 225 WEST STATION SQUARE SUITE 700 PITTSBURGH PA 15219 1 0 0 0 Deferred Share Units 2016-12-09 2016-12-09 4 A 0 1087.2897 43.495 A Common Stock 1087.2897 1087.2897 D Deferred Share Units are credited to an account in the reporting person's name maintained by WESCO International. Each Deferred Share Unit is the economic equivalent of one share of WESCO International common stock. The Deferred Share Unit Account balance becomes eligible for distribution, only in the form of WESCO International common stock, upon termination of service as a Director. The price is based on the average of the high and low trading prices for WESCO International's common stock as of the first trading day in January of 2016. /s/ Samantha L. O'Donoghue, Attorney-In-Fact 2016-12-09