Continental Airlines (IATA: CO, ICAO: COA, Call sign: CONTINENTAL) was a major American airline that merged with United Airlines. On May 3, 2010, Continental Airlines, Inc. and UAL, Inc. (the parent company of United Airlines) announced a merger via a stock swap, and on October 1, 2010, the merger closed and UAL changed its name to United Continental Holdings, Inc. During the integration period, both airlines were running separate operations under direction of a combined leadership team of the new parent company based in Chicago. The merger transaction is estimated to be worth (USD)$3.2 billion. On November 30, 2011, United Airlines was issued a single operating certificate. From a technical regulatory standpoint, Continental Airlines then ceased to exist as a separate air carrier. United and Continental are now considered one airline by the Federal Aviation Administration (FAA), and Continental pilots now use the "United" call sign in air traffic control. The reservations systems were merged at 1 am on March 3, 2012 and Continental.com was rebranded to be the new united.com. Ground operations will remain somewhat separate until early in 2012. The airline's last flight, Continental Flight 1267 occurred on March 2, 2012.