Zeller plans to convert most of the retail space to office space, which when added to the 485,000-sf office tower, would give the building a total of 635,000-sf of commercial space, Gearen says. While the retail section of the building is largely vacant - in part due to plans to convert much of the space to other uses - the office portion has done well, with all but four the tower's 37 floors occupied. It's unclear what other changes the new landlords may bring to the retail portion of the building, which still has a small number of tenants.

The purchase of the World Trade Center reinforces Zeller's position as one of the larger landlords in the Twin Cities. ''We own and manage about 2.5 million sf in the Twin Cities - that is about 5% of the office space,'' Gearen told GlobeSt.com. Among Zeller's other Twin Cities holdings are the 450,000-sf Wells Fargo Plaza in Bloomington, MN, and the 341,000-sf International Center, 271,000-sf Kinnard building and 380,000-sf One Financial Plaza, all in downtown Minneapolis.

As a longtime tenant in the Wells Fargo Plaza, Morrow says Wells Fargo was only interested in the World Trade Center deal if Zeller was the owner.