Buth, along with MB Real Estate's Kathleen Bertrand, represented building ownership in the lease transaction. Lisa Konieczka, Cal Wessman and Bill Sheehy, both with CB Richard Ellis, represented Blue Cross Blue Shield Association, the nonprofit national association for the 39 independent, locally operated Blue Cross Blue Shield Plans.

Blue Cross Blue Shield Association (BCBSA) is the largest tenant in the building, occupying all of the second through the sixth floors, in addition to parts of the eighth and ninth floors. BCBSA has been a tenant in the building since 1995. BCBSA is the "association which supports the plan groups," Buth says. One of the plan groups is Health Care Services Corp., operating as Blue Cross Blue Shield of Illinois, which expanded recently to 263,000 sf at 111 E. Wacker and also expanded at 300 E. Randolph St., as reported by GlobeSt.com.

The two-building office complex consists of a 44-story building at 205 N. Michigan Ave. and a 25-story tower at 225 N. Michigan Ave and has a total of more than 1.9 million sf of rentable space. Michigan Plaza is currently 78% leased, Buth tells GlobeSt.com. Major tenants include Omnicom, MCI and Fox Television. Asking lease rates range from $28 per sf to $32 per sf gross, he says. MB Real Estate has been the management company for Michigan Plaza since 2005. MB Real Estate has completed leases for more than 265,800 sf at Michigan Plaza so far for the year. The complex is owned by Loeb Partners Realty LLC, based in New York City, which acquired the property in December 2004 for approximately $273 million, sources say.