Com-Psych Corp., a provider of employee assistance programs and other employee services, is subleasing 53,002 square feet of the former Navistar International Corp. headquarters in NBC Tower, 455 North Cityfront Plaza Drive. Chicago-based ComPsych will move this summer from the building's 24th floor, where it has about 36,000 square feet, to the 11th and 13th floors. The 11th floor totals 29,919 square feet and the 13th floor 23,083 square feet. The sublease runs through December 2009. Navistar, which moved to the western suburbs in a cost-cutting move, is still looking for tenants to take its remaining 82,000 square feet. Todd Lippman of Insignia/ESG Inc. represented ComPsych, while Lyle Levin of Julien J. Studley Inc. represented Navistar. Florida-based investment company Sunbelt Associates owns the 850,000-square-foot tower, which is 96% leased but has more than 108,000 square feet of sublet space available.