US Airways has its headquarters in Tempe, Arizona. As part of the merger, US Airways will also leave the Star Alliance to join the oneworld global airline alliance, of which American Airlines is an anchor member along with British Airways, the people familiar with the matter said. The airlines are estimating that a merger will bring about $1 billion in revenue and cost benefits, they said. Horton rebuffed an aggressive takeover push from US Airways early in the bankruptcy process, saying the airline preferred to exit court protection on its own and consider a deal later.