"Emirates has today announced an historic USD 9.2 billion deal with Rolls-Royce for Trent 900 engines and a long-term TotalCare package," it said in a statement.
The engines will power 50 Airbus A380s that were ordered at the Dubai Air Show in 2013 and will start entering service next year.
The deal -- the biggest ever for Rolls-Royce, and one of the largest ever export orders for a UK-based company -- was unveiled at a press conference in central London by Emirates president Tim Clark.
"These improvements have been decisive factors in our selection of the product for 50 of our A380s.
"Today's announcement is significant not only because it cements the partnership between Emirates and Rolls-Royce, but also because of the large and sustained economic impact that this will have on aviation manufacturing in the UK and Europe.