The ATC headquarters was sold by a joint venture of Pewaukee-based Interstate Partners and Milwaukee-based Zilber Property Group to Chicago-based ATWI001 Owner LLC.
The sale is the largest single-property commercial real estate transaction in the state so far this year, said Nathan Winkel, regional director of analytics in Wisconsin for Xceligent.
The 13.86 acre property located at W234 N2000 Ridgeview Parkway Ct., Pewaukee, has a three-story, 123,833-square-foot office building and a 33,600-square-foot industrial building, according to Xceligent. The buildings are three years old. The property is known as RidgeView Office Center III.
American Transmission Company, which owns and operates a high-voltage electric transmission system in portions of Wisconsin, Michigan, Minnesota and Illinois, occupies the entire complex and plans to remain there. The company has about 375 employees at its corporate headquarters and about 575 employees company-wide.
"Nothing is changing here," said ATC spokeswoman Anne Spaltholz. "This remains our headquarters. We have a new landlord."
More information about ATWI001 Owner LLC was not immediately available. The entity's registered agent is CT Corporation System in Madison, according to state records.