MINNETONKA, MN—OneBeacon Insurance Group has renewed and expanded its lease at 601 Tower at Carlson here, bringing the 288,458-sq.-ft. property 95 percent leased.

The company has renewed, and about doubled, its 23,764-sq.-ft. lease, and now occupies a total of 45,092 sq. ft. on floors five, six and seven of 601 Tower at Carlson. The firm has been a building tenant since 2006.

The 15-story tower is in the Carlson Center master-planned office park, close to Interstates 494 and 394. The tower features a two-story marble atrium, a 55-foot rotunda and a circular staircase. Onsite amenities include a café, outdoor amphitheater and fitness center. 

Tom Wille with the Tampa, Fla.-based CLW Real Estate Services Group, represented OneBeacon. Mike Marinovich with CBRE in Minneapolis negotiated the lease on behalf of KBS Real Estate Investment Trust II, which purchased the property in 2011.