"After reviewing several options in the West Loop, 250 South Wacker met all the needs of National Surgical Hospitals' office space requirement," Karmin says. "The smaller floor plates offered National Surgical Hospital prominent identity with great views over the Chicago River."

The building, which was originally constructed in the 1960s, underwent a $24 million renovation in recent years. The work included retrofitting of electrical, heating and air-conditioning systems, new elevators and cabs, atrium lobby and updated exterior. In April 2007, it was purchased for $57 million by AEW Partners V, headquartered in Boston, from former owners D2 Realty Cos.

The property is seeking LEED certification and is registered with the US Green Building Council. It offers proximity to Union Station in the West Loop, where overall occupancy is around 87%, according to Transwestern's Q3 office market report. Asking lease rates there have recently been around $26 per square foot.