United Continental Holdings, Inc. (UAL) is a holding company and its principal subsidiary is United Air Lines, Inc. (United). The Company transports people and cargo through its mainline operations. It has global air rights in North America, Asia-Pacific, Europe, Middle East, Africa and Latin America. The Company, through United and its regional carriers, operates flights from its hubs at Newark Liberty International Airport (Newark Liberty), 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 regional carriers to provide regional jet and turboprop service branded as United Express. These regional operations are an extension of the Company's mainline network.