Qatar Airways appears set to take additional Airbus A350-1000s through the conversion of its order for A350-800s.
The Doha-based carrier is dropping its commitment to the -800, the smallest member of the twinjet family, in favour of larger variants.
Qatar Airways has 20 A350-800s on order which formed part of a broad agreement for 80 A350s placed in June 2007.
But the airline's chief executive, Akbar Al Baker, says that it is converting these to larger models.
Speaking in Doha after the airline's first Boeing 787 arrived, Al Baker initially pointed to a switch to -900s. But a source close to the situation indicates that some of the -800s will be converted to A350-1000s - although the precise split has yet to be clarified.
Qatar Airways' original order included 20 -1000s but Al Baker subsequently expressed dissatisfaction over the aircraft after Airbus redesigned the twinjet and postponed its entry into service to 2017.
Airbus has since worked to convince the Gulf carrier that it has improved the -1000. The airframer has not confirmed any changes to Qatar Airways' A350 order.
Qatar Airways had been the launch customer for the A350-800, and Airbus has yet to identify a successor. The carrier's decision casts greater uncertainty over the type's future, in the wake of stagnant sales and the migration of several A350-800 customers to the two larger models.