Delta Air Lines is to move a number of transatlantic departures to align with partner Virgin Atlantic at Heathrow Terminal 3.
The switch from April 2 includes New York-JFK, Boston and a new Seattle service.
Delta will also operate a second daily service between Heathrow and Detroit from June 1 in co-operation with Virgin Atlantic.
Virgin chief executive Craig Kreeger said: “We are working on a series of improvements to enhance the travel experience for our customers.
“We already co-locate together at New York’s JFK airport and moving some of Delta’s key business flights to join Virgin Atlantic at Heathrow’s Terminal 3 will enhance convenience and reduce connection times. This demonstrates how our new partnership is going to be making a real difference for customers.”
Virgin Atlantic is moving its Heathrow to Newark service from a late afternoon to a morning departure, while an earlier departure on the return flight means passengers can be in central London for the start of the working day.
This service is part of nine daily flights between Heathrow and the New York area by the joint venture partners.
Virgin’s Heathrow-Boston service has been re-timed to depart two hours later in the afternoon to complement Delta’s morning departure.
Delta president Ed Bastian said: “A key reason for our joint venture was to offer customers more choice and convenient schedules, especially for our business travelers.
“With our Seattle service, Delta will add its sixth non-stop destination between London and the US. Combined, the Delta-Virgin partnership now offers our customers 33 daily non-stop flights across the Atlantic.”