United Airlines Holdings Inc., formerly United Continental Holdings, Inc., is a holding company and its principal, wholly-owned subsidiary is United Airlines, Inc. (United). The Company transports people and cargo throughout North America and to destinations in Asia, Europe, the Middle East and Latin America. Through United and its regional carriers, it operates across five continents, with hubs at Newark Liberty International Airport (Newark), Chicago O'Hare International Airport (Chicago O'Hare), Denver International Airport (Denver), George Bush Intercontinental Airport (Houston Bush), Los Angeles International Airport (LAX), A.B. Won Pat International Airport (Guam), San Francisco International Airport (SFO) and Washington Dulles International Airport (Washington Dulles). It has contractual relationships with various regional carriers to provide regional aircraft service branded as United Express.