The deal is aid to be worth as much as €13bn
Dubai-based airline Emirates has signed a Memorandum of Understanding (MoU) to buy up to 36 Airbus A380 aircraft.
The agreement was signed on Thursday at the airline's headquarters in Dubai.
The deal, valued at US$16bn (€13bn), is for 20 A380s and an option for 16 more with deliveries to start in 2020.
The agreement is seen as a lifeline to the Airbus aircraft, which has been in service for just 10 years.
Earlier this week, Airbus confirmed that securing the deal was critical for the A380.
The European aircraft maker said it would have no choice but to close production of the model if the deal fell through, despite interest in smaller orders from others.
Negotiations between Airbus and Emirates had broken down at the last minute at the Dubai Airshow in November, when the Middle East carrier placed an order for 40 smaller 787 aircraft made by Airbus's US rival Boeing.
The chairman and chief executive of Emirates, Sheikh Ahmed bin Saeed Al Maktoum, said: "We’ve made no secret of the fact that the A380 has been a success for Emirates.
"Our customers love it, and we’ve been able to deploy it on different missions across our network, giving us flexibility in terms of range and passenger mix.
"Some of the new A380s we’ve just ordered will be used as fleet replacements. This order will provide stability to the A380 production line.
"We will continue to work closely with Airbus to further enhance the aircraft and onboard product, so as to offer our passengers the best possible experience."
John Leahy, chief operating officer for Airbus, added: "This aircraft has contributed enormously to Emirates' growth and success since 2008 and we are delighted that it will continue to do so.
"This new order underscores Airbus’ commitment to produce the A380 at least for another 10 years."
Following delivery of its first A380 in July 2008, Emirates took its 100th A380 on the November 3rd 2017 in Hamburg, Germany.
To date, 222 A380s have been delivered to 13 airlines.
The A380 can accommodate 575 passengers in four classes, and was revealed on this day in 2005.