United Airlines has signed a transatlantic feeder flight codeshare deal with Germanwings.
The agreement, which starts immediately, means the German carrier now offers codeshare flights as feeders for United long-haul services from London, Berlin and Hamburg.
These connection flights will show both a United UA flight number and Germanwings' own 4U code.
The two airlines have also signed a loyalty agreement allowing United Mileage Plus members to exchange air miles for flights across the entire Germanwings network, and for Germanwings passengers to earn Mileage Plus miles when booking feeder flights via united.com or from travel agencies.
United and Germanwings also have plans for further collaborative measures.
A statement said: "The partnership between the two airlines is to be consolidated further over the coming months, to offer passengers further advantages and make transatlantic trips with Germanwings and United Airlines even easier."
Last month, it emerged that United will axe three weekly flights on its Houston to Tokyo Narita route from December (see news, October 28).