Pratt & Whitney is an American aerospace manufacturer with global service operations. It is a subsidiary of United Technologies Corporation (UTC). Pratt & Whitney's aircraft engines are widely used in both civil aviation (especially airlines) and military aviation. Its headquarters are in East Hartford, Connecticut. As one of the "big three" aero-engine manufacturers, it competes with General Electric and Rolls-Royce, although it has also formed joint ventures with both of these companies. In addition to aircraft engines, Pratt & Whitney manufactures gas turbines for industrial and power generation, and marine turbines. As of 2014, the company reported having 31,500 employees supporting more than 11,000 customers in 180 countries around the world. In 2013, Pratt & Whitney's revenue totaled $14.5 billion.