The top 14 floors of the 50-story building will become condominiums, with pre-sales expected to begin in May. A new entrance to the condominium portion of the building will be added to the ground floor. The rest of the 35-year-old building, more than one million sf, will remain office space. Vacancy is 16%, according to Black's Guide, with asking net lease rates beginning at $15 per sf. Seyfarth Shaw is leaving 217,000 sf by the end of the year in favor of space at Citadel Center at 131 S. Dearborn St. In addition, Barton Inc. also is leaving for 90,000 sf at 1 S. Dearborn St.

Meanwhile, the joint venture is betting there is room for more units in the Downtown condominium market, which has been buoyed by improvements to Millennium Park, a block east of its building. Within a few blocks, buildings at 5 N. Wabash Ave., 6 E. Monroe St., 8 E. Randolph St. and 330 S. Michigan Ave. have been redeveloped as loft condominiums, while 8 W. Monroe St. is in the works. Newer construction includes buildings at 20 N. State St. and the 356-unit Heritage at Millennium Park.

GlenStar Properties LLC will add the office space to its four-million-sf management portfolio, as well as oversee redevelopment of the upper floors. Two architectural firms, Pappageorge/Haymes Ltd. and Goettsch Partners, have been hired by the joint venture. GlenStar Properties LLC also handled negotiations with Jones Lang LaSalle brokers representing German syndicator GENO Asset Finance FmbH.