Parker accused the government of trying to change the rules.
"They approved other mergers," he said. "Our merger passes muster by 10 miles."
But Mark Ryan, the director of litigation in the Justice Department's Antitrust Division, said that the Justice Department's approval of past mergers was "not a defense" for this one.
Ryan cited a number of concerns outlined in the government's Aug. 13 complaint, including the transparency of pricing, higher ticket prices and checked-baggage fees, the possibility of anticompetitive coordination with other airlines, the end of head-to-head competition for numerous city pairs, the end of a popular discount program, and the combined airline's dominance at Washington's Reagan National Airport.
Critics of airline industry consolidation said the move was long overdue.
"They brought this case three mergers too late," said Joseph Bauer, a law professor at the University of Notre Dame.
Meanwhile, a federal bankruptcy judge in New York is expected to rule on the merger in September. The merger is American's plan to exit from Chapter 11 bankruptcy, and Judge Sean Lane indicated Thursday that he's inclined to approve it on Sept. 12, but he wants to hear more about the airlines' response to the government's case.
Ryan said Friday that American could stand on its own.
"We think American was poised to come out of bankruptcy as a vigorous competitor," he said.
After meeting with the two sides behind closed doors Friday, Kollar-Kotelly scheduled the trial for the week of Thanksgiving. The trial could last from 10 to 15 days, with both sides seeking testimony from airline executives and economists, among others.
"That is a pretty accelerated timeframe," Bauer said. "To do it within a two- to three-month timeframe would be pretty quick."