Northwestern Mutual has paid $6.86 million for a downtown Milwaukee building that it will convert to new office space, providing elbow room for a larger demo/construction project.

The building at 733 N. Van Buren St. is just west of the insurance company's main downtown campus. Northwestern last year announced it would buy the building from developer Van Buren Management Inc. The sale closed Jan. 7. Northwestern hopes to move employees this summer after an extensive renovation project.

The buy is part of Northwestern's plan to demolish a building at its downtown campus and replace it with an office tower that will cost more than $300 million. About 500 employees who work in that targeted building will relocate to the Van Buren office during the interim. Work on the acquired building will begin immediately, and this spring a skywalk will be constructed over Van Buren Street to connect the office to Northwestern's main campus. Van Buren Management said tenants occupying the Van Buren building were relocated. Even after Northwestern opens its 830,000-840,000-square foot office tower, it intends to maintain the Van Buren building.