DeAngulo and Russ Cora, also with Cape Horn Group, represented the building owner in the sales transaction. Stuart Eng and Howard Ecker, both with Howard Ecker and Co., represented the two law firms in the transaction. Both firms are currently at 161 N. Clark St. and will be moving into 55 W. Wacker next week, DeAngulo tells GlobeSt.com.

The building has been vertically subdivided and the floors are being sold in a way similar to office condominiums, DeAngulo says. The subdivision allows, for example, one of the law firms to sell their part of the floor without having to go before the city council or a zoning commission, he says. "Owning our office space allows us to lock in our monthly real estate costs while building equity," O'Rourke & Moody partner Michael O'Rourke said in a statement. "We are no longer confronted with annual lease increases or tough landlord negotiations."

Cape Horn, based in Miami Beach, has sold nearly 40,000 sf in the column-free building to occupants since last September when it began marketing the facility. Buyers have included a financial institution, an entrepreneur who distributes diesel engines and an investor, DeAngulo says. The building was constructed in 1968 and renovated in 1987. An affiliate of Cape Horn acquired the building, in 2006, for $36 million, sources say. Cape Horn has renovated the common areas and upgraded the elevators, security system and heating, ventilation and air conditioning system. DeAngulo said he could not give an estimate for the cost of the renovations but that it is in the "seven figures." Cape Horn also owns the LaSalle-Wacker Building, 221 N. LaSalle St., and has also vertically subdivided the building to sell floors to occupants, DeAngulo says.