Singapore Airlines announced that it will not extend the lease on its first Airbus A380 aircraft when it expires next year, a significant blow for Airbus, as it seeks to bolster new sales of the world’s largest airliner.

Singapore Airlines’ first five A380s are on 10-year leases, with options to extend.

“The first contract expires in October 2017, and we have decided not to extend it”, Singapore Airlines spokesperson told the Aviation Tribune. “This decision was the result of a regular review of our fleet requirements, and decisions will be made on the four others later”.

The Singapore flag carrier was the A380 launch customer, when it entered commercial service in October 2007. It currently has 19 A380s in its fleet, with five more on firm order with Airbus, deliveries of which will start in the second half of 2017.

Besides Singapore Airline, another 12 airlines are currently operating the A380: Singapore Airlines, Qantas, Emirates, Qatar Airways, Air France, Lufthansa, Korean Air, China Southern Airlines, Malaysia Airlines, Thai Airways, British Airways, Asiana and Etihad.

Nineteen customers have ordered the A380. Total orders for the A380 stand at 319 as of August 2016.

The biggest customer is Emirates, which has ordered or committed to order a total of 142 A380s as of 31 August 2016. One VIP order was made in 2007 but later cancelled by Airbus. The A380F version totalled 27 orders before they were either cancelled (20) or converted to A380-800 (7), following the production delay and the subsequent suspension of the freighter programme.

In hopes of raising the number of orders placed, Airbus announced discounts to airlines who placed large orders for the A380. Emirates soon after, ordered 50 aircraft, totalling $20.75 billion. Airbus gave a $2.75 billion total discount, equal to $55 million in savings per aircraft for Emirates.

Airbus says that some A380s may not be delivered to customers or even built. This decision came when Airbus had not met the ‘Accord and Satisfaction’ for three already built aircraft for an undisclosed Japanese airline.

Among customers that have ordered superjumbos yet remain undecided about actually taking them is Virgin Atlantic, with six units on the order book. Qantas had also planned to top up its existing fleet by as many as eight airplanes, an expansion that has been thrown into doubt amid a cost-cutting drive. Amedeo, an aircraft lessor that ordered 20 A380s, has yet to find a single client for the jet.