Willis Towers Watson (NYSE: WLTW) was formed as a merger of equals between London based Willis Group Holdings plc and Towers Watson & Co. Willis Towers Watson is an Irish-domiciled global multinational risk management, insurance brokerage and advisory company. The firm has roots dating to 1828 and is the third largest insurance broker in the world.. Currently, Willis Towers Watson operates in more than 140 countries and has a workforce of more than 45,000 employees. (Source: Wikipedia).