Chicago’s iconic Sears Tower, the tallest building in the Western hemisphere, is to be renamed after securing a new tenant.

Global insurance broker Willis Group has leased more than 140,000 sq ft of offices at the 1,451 ft tall tower on South Wacker Drive in Chicago.

Willis will now rename the building, which first opened in 1973, the Willis Tower.

The company, represented by Cushman & Wakefield, will be consolidating five of its area offices in the building.

Willis Tower is owned by 233 S. Wacker Drive LLC, a real estate investment group formed in 2004 to purchase the tower.

The company is owned by a consortium of investors including New York City-based partners Joseph Chetrit, Joseph Moinian and Steve Bederman of Moinian Group and Yisroel Gluck and John Huston, of American Landmark Properties.

Willis’s move is expected to be completed towards the end of the summer.