Delta Air Lines said today that it will buy almost half of Virgin Atlantic for $360 million as it tries to catch up to rivals in the lucrative New York-to-London travel market.

Delta plans to form a joint venture with Virgin Atlantic so they can sell seats on each other’s flights, share the costs and profits, and set the flight schedules in ways that help both airlines.

American Airlines has a similar deal with British Airways.

Because Delta would be setting fares and schedules in coordination with an airline it used to compete with, it said it will need antitrust approval from U.S. and European regulators in order to form a joint venture. Delta said the share purchase will happen with or without antitrust approval.

Delta is aiming to have the joint operation running by the end of 2013.

The deal won’t add flights between the U.S. and Britain. But travel will be more seamless.