X0306 4 2023-02-16 0 0000929008 WESCO INTERNATIONAL INC WCC 0001667708 Cooney Anne M 225 WEST STATION SQUARE DRIVE SUITE 700 PITTSBURGH PA 15219 1 0 0 0 Common Stock 2023-02-16 4 A 0 1018 0.00 A 3131 D Common Stock 2023-02-17 4 F 0 5 168.71 D 3126 D The Reporting Person received a grant of 1,018 restricted stock units (RSUs) under the Issuer's long-term incentive plan. Each RSU represents a contingent right to acquire one share of Issuer's common stock. The RSUs vest in full on the first anniversary of the grant date. The Reporting Person has reported prior awards of RSUs in Table II of Form 4. The total reported in Column 5 includes 1,018 newly awarded RSUs, 1,433 previously reported RSUs, and 680 shares of common stock. Represents tax withholding on the vesting of RSUs that were granted February 17, 2022. /s/ Michele Nelson, as Attorney-in-Fact 2023-02-21