Emirates and Airbus have firmed up an earlier memorandum of understanding and signed a contract for the 20 additional A380s with a further 16 options to be confirmed at a later date.
The total agreement for 36 aircraft is valued at US$16 billion based on latest list prices.
Deliveries are to start as early as 2020 and could see the A380 programme through to the end of the decade.
The agreement was signed at the World Government Summit by sheikh Ahmed bin Saeed Al Maktoum, chairman of Emirates Airline, and Mikail Houari, Airbus president for Africa and Middle East.
Sheikh Mohammed bin Rashid Al Maktoum, ruler of of Dubai, and Edouard Philippe, prime minister of France, were also present.
Al Maktoum said: “This agreement underscores our commitment to the A380 programme, providing stability to the A380 production line and supporting thousands of high-value jobs across the aviation supply chain.
“For Emirates, the A380 has been a successful aircraft for our customers, our operations, and our brand. We look forward to continue working with Airbus to further enhance the aircraft and onboard product.”
The A380 is an essential part of the solution to sustainable air traffic growth, alleviating congestion at busy airports by transporting more passengers with fewer flights.
The aircraft is the best way to capture growing world air traffic, which doubles every 15 years.
To date more than 200 million passengers have already enjoyed the unique comfort of flying on board an A380.
Every two minutes an A380 either takes off or lands at some of the 240 airports around the world, ready to welcome this magnificent aircraft.
To date, 222 A380s have been delivered to 13 airlines.