WASHINGTON, Nov 3 (Reuters) - The Trump administration

on Monday asked a U.S. appeals court to reject a bid by Delta

Air Lines ( DAL ) and Aeromexico to halt an order forcing them

to unwind a joint venture that lets the carriers coordinate

scheduling, pricing and capacity for U.S.-Mexico flights.

The Transportation Department "validly decided to no longer

authorize legalized collusion by two formerly competing airlines

that control almost 60% of operations at the fourth-largest

international gateway to and from the United States," the

government said in a filing, citing Mexico City flights.