An Emirates Airbus A380 airliner prepares to land at Nice international airport, France, January 18, 2018. REUTERS/Eric Gaillard

DUBAI (Reuters) - Emirates signed a contract on Sunday to buy as many as 36 Airbus AIR.PA A380 aircraft worth as much as $16 billion at list prices, firming up an order that is crucial to the future of the world's biggest passenger jet.

The order, for 20 of the double-decker planes with an option for 16 more, was originally announced on a provisional basis in mid-January. Deliveries are to start as soon as in 2020, the Dubai-based carrier said.

Airbus had previously said it would have to end production of the A380 if it failed to secure the huge Emirates deal.

Alongside the contract signing, visiting French Prime Minister Edouard Philippe and Emirates chairman Sheikh Ahmed bin Saeed al-Maktoum discussed the expansion of air services between France and the United Arab Emirates, the airline said without elaborating.

The latest order brings Emirates’ commitment to the A380 program to 178 aircraft, it said, adding that it was evaluating engine options for the new planes.