X0508 4 2023-09-29 0 0000929008 WESCO INTERNATIONAL INC WCC 0001611129 Kulasa Matthew S 225 W STATION SQUARE DRIVE SUITE 700 PITTSBURGH PA 15219 0 1 0 0 SVP, Corp. Controller & CAO 0 Common Stock 2023-09-29 4 A 0 2.82 0.00 A 1558.3294 D Represents dividend equivalent rights ("DERs") in connection with the Issuer's quarterly dividend and accrued to the Reporting Person on restricted stock units ("RSUs") held by the Reporting Person. Each DER is the economic equivalent of one share of Issuer's common stock and vests on the same schedule as the underlying award. /s/ Michele Nelson, as Attorney-in-Fact 2023-10-03