Corporate Headquarters WESCO International, Inc. Suite 700 225 West Station Square Drive Pittsburgh, PA 15219-1122 Phone: 412-454-2200 www.wesco.com Investor Relations For questions regarding WESCO, contact Daniel A. Brailer, Treasurer and Director of Investor Relations, at dbrailer@wesco.com. A copy of the Company’s Annual Report on Form 10-K or other financial information may be requested through our web site (www.wesco.com) or by contacting Investor Relations. Common Stock WESCO International, Inc. is listed on the New York Stock Exchange under the ticker symbol WCC. Annual Meeting The Annual Meeting of stockholders will be held on May 18, 2005, at 2:00 p.m., CST, at: Sofitel Chicago O'Hare 20 East Chestnut Street Chicago, IL 60611

Transfer Agent and Registrar Mellon Investor Services, L.L.C. Overpeck Center 85 Challenger Road Ridgefield Park, NJ 07660-2108 www.melloninvestor.com/isd Phone: 1-800-756-3353 Outside the U.S.: 1-201-329-8660 The hearing disabled can access TDD service at: 1-800-231-5469 (within the U.S.) or 1-201-329-8354. Independent Registered Public Accounting Firm PricewaterhouseCoopers LLP Pittsburgh, PA