Colliers, Bennett, & Kahnweiler President and CEO David R. Kahnweiler, SIOR, was named vice chairman of the Board of Directors for Colliers International. As president and CEO of the firm, Kahnweiler is responsible for the strategic planning of the overall firm. He has more than 23 years of experience in the real estate industry. Kahnweiler is a senior vice president of the Better Boys Foundation, a Chicago-based social agency serving children and families of blighted areas. He also serves on the board of the Chicago Development Council and the Chicagoland Chamber of Commerce.