Willis Tower
Sears' naming rights ended in 2003, but the building was still called the Sears Tower for many years. In March 2009, the British insurance company Willis Group Holdings agreed to rent a part of the building and got the naming rights. On July 16, 2009, the building was officially renamed the Willis Tower. On August 13, 2012, United Airlines said they were moving its corporate headquarters from 77 West Wacker Drive to Willis Tower.