LONDON — The Emirates airline says it will buy $9.2 billion worth of Rolls Royce engines, the largest ever order for the engine maker.

The deal announced Friday calls for the purchase of Trent 900 engines and a long term maintenance package.

The engines will power 50 Airbus A380 aircraft set to enter service in 2016.

The move by the Gulf carrier marks a setback for Engine Alliance, a joint venture by General Electric and Pratt & Whitney. It is the first time that Emirates, based in Dubai, has ordered Rolls-Royce engines for its superjumbo fleet.

Emirates President Tim Clark says the airline was impressed by Rolls’ commitment to improve economic and operational performance.