Willis Group

Willis Group Holdings plc was a multinational risk advisor, insurance brokerage and reinsurance brokerage company with its headquarters in the Willis Building in London until its merger with financial services company Towers Watson in 2016. 
It was the world's third-largest insurance broker. Willis has around 400 offices in 120 countries and about 18,000 employees.
The 110-story Sears Tower in Chicago was renamed the Willis Tower in July 2009 since Willis bought the name rights of the building.