American Airlines parent AMR Corp. and US Airways Group Inc. are beginning a series of important meetings with U.S. antitrust regulators, dubbed “the end game” that could shape the details of the world’s largest airline merger, the Wall Street Journal reported today. U.S. Department of Justice staffers who have been reviewing the planned merger for nearly six months will use the meetings with the carriers and their lawyers to go over the government’s questions and concerns, possibly raising the prospect of concessions to win its backing. The U.S. meetings come as American and US Airways offered to divest a pair of daily slots at London’s Heathrow Airport in order to win European Union backing for their planned merger. The two airlines, which announced their merger plan in mid-February, have said that they expect the deal to win antitrust approvals and hope to close the transaction in the third quarter. The deal, which provides AMR a route out of bankruptcy-court protection, currently is being voted on by AMR’s creditors and is slated for a possible confirmation hearing in bankruptcy court on Aug. 15.