United States regulators have approved an alliance between Switzerland's new national carrier "swiss" and American Airlines.
The two companies signed an agreement in March to start code sharing to 35 destinations in the US and Europe from May 15.
The sharing arrangements are set to expand to a total of 128 "swiss" destinations and 234 American Airlines destinations.
Both will also join forces on their frequent flyer programmes, adding to one of the world's largest customer networks.
In March, André Dosé, the "swiss" chief, portrayed the alliance as confirmation that the new airline was being taken seriously.
By joining with American Airlines, the world's biggest carrier, "swiss" customers will earn and collect air miles from within the "oneworld" alliance, which includes British Airways, Cathay Pacific, Qantas and Iberia.
The US department of transportation gave the green light on Thursday.