The decision was taken following “on-going discussions with the airline in light of their fleet requirement review”, Airbus said on Wednesday.
Airbus added that it was still very confident in the A350 programme and said there were almost 750 planes on the order book ready to enter service.
“The programme of test flights for the A350 is progressing well and is on schedule for certification (by the Aviation Authorities) in the coming months,” said Airbus.
The price of shares in Airbus Group, of which the airliner business is the biggest element, fell by 3.14 percent to 52.18 euros in early trading. The overall French CAC 40 index was down by 0.31 percent.
The cancellation of such a big order would seem to be a serious setback for the European manufacturer, based in Toulouse. John Leahy, the boss of Airbus was due to make a statement later on Wednesday.
Emirates is one of Airbus’s biggest clients and placed the order for A350s in 2007. The first deliveries were scheduled for 2019.
In London, aero-engine maker Rolls-Royce said that the cancellation would reduce the value of its order book by 2.6 billion pounds (3.2 billion euros, $4.3 billion).