DALLAS – American Airlines and US Airways agreed Wednesday to a merger that will create the world's biggest airline. The deal caps a turbulent period of bankruptcies and consolidation that leaves the U.S. airline industry dominated by four big carriers.

The boards of American parent AMR Corp. and US Airways approved the deal late Wednesday, according to four people close to the situation.

The carrier will keep the American Airlines name but will be run by US Airways CEO Doug Parker. American's CEO, Tom Horton, will serve as chairman of the new company until mid-2014, these people said. They requested anonymity because the merger negotiations were private.