United Airlines, Inc., commonly referred to as "United", is an American major airline headquartered in Chicago, Illinois. It is the world's largest airline when measured by number of destinations served. In the late 1920s, just prior to the use of the United Airlines name, The Boeing Company, currently one of the world's largest aircraft manufacturers, operated a predecessor airline.United operates out of nine airline hubs in the continental United States, Guam, and Japan. George Bush Intercontinental Airport in Houston is United's largest passenger carrying hub handling 16.6 million passengers annually with an average of 45,413 passengers daily, while Chicago-O'Hare is its largest hub in terms of daily departures.
The company employs over 88,500 people while maintaining its headquarters in Chicago's Willis Tower (formerly known as Sears Tower). Through the airline's parent company, United Continental Holdings, it is publicly traded under NYSE: UAL with a market capitalization of over $18 billion as of September, 2014.
United's main competitors in its domestic market are Delta Air Lines, American Airlines, and Southwest Airlines. United is using Continental's air operator's certificate and it surrendered its original certificate when the merger closed. As of November 2013, Silver Airways and SkyWest Airlines flying United Express routes were awarded $31,660,211 in annual federal subsidies for Essential Air Services that they provided to rural airports in the U.S. that would otherwise be uneconomical to serve.
