Sears its naming rights to the building expired in 2003 it remained the Sears Tower until early 2009. In March 2009 London-based insurer Willis Group Holdings, Ltd., was given the building's naming rights to encourage them to occupy the building. The official renaming as the "Willis Tower" took place on Thursday, July 16, 2009, during a public ceremony hosted by Willis Group Holdings. In the 1990s, the company began divesting itself of many non-retail entities, which were detrimental to the company's bottom line. Sears spun off its financial services arm which included brokerage business Dean Witter Reynolds and Discover Card. It
Park Tower (Chicago) Park Tower (Chicago) Park Tower is a skyscraper located at 800 North Michigan Avenue in Chicago, Illinois. Completed in 2000 and standing at tall with 70 floors — 67 floors for practical use, it is the twelfth-tallest building in Chicago, the 43rd-tallest building in the United States, and the 83rd-tallest in the world by architectural detail. It is one of the world's tallest buildings to be clad with architectural precast concrete (the Transamerica Pyramid Building in San Francisco is taller). It is one of the tallest non-steel framed structures in the world—it is a cast-in-place concrete framed structure. This building