The airlines argue that their merger would benefit passengers by providing more flights to more airports, in the United States and abroad, and offer a stronger counterweight to Delta and United. The federal challenge to the merger followed a tumultuous period of restructuring for American Airlines, which filed for bankruptcy in 2011. The reorganization was approved by a federal judge in September, subject to Justice Department approval of the merger. As part of the plan, American agreed to merge with US Airways, a move that received the backing of creditors and its three main labor groups. Shares of American's parent, the AMR Corporation, jumped nearly 25 percent Monday on the news about the settlement talks.