The tallest building in the U.S. – Sears Tower – will become Willis Tower under a deal that would consolidate five Chicago-area property-casualty insurance offices into the tower.

The 110-story tower, the fifth-largest building in the world, will be renamed Willis Tower under a leasing deal between the London-based insurance broker and the New York-based owners of the tower, according to published reports.

Sears Roebuck & Co. has occupied the tower and claimed naming rights since 1992.

Willis will lease 140,000 square feet of space, about 3.5% of the 3.8-million-square-foot structure, so about 500 can move this summer. Willis officials will pay $14.50 per square foot for rent, with naming rights included.

“Having our name associated with Chicago’s most iconic structure underscores our commitment to this great city, and recognizes Chicago’s importance as a major financial hub and international business center,” said Joseph Plumeri, chairman of Willis Group Holdings, told the Chicago Sun-Times newspaper.

Sears Tower opened in 1973, serving as the company’s corporate headquarters for 19 years.

In 2004, a group of investors, including American Landmark Properties Ltd., took ownership of Sears Tower, whose naming rights with Sears expired several years ago, reports say.