Airbus will not hand over the first A350-1000 until 2018, after the airframer agreed a revised delivery schedule with launch customer Qatar Airways.
Qatar Airways has 37 of the largest A350 variant on order and Airbus had been aiming to deliver the first aircraft by the end of this year.
But the airframer tells FlightGlobal that it has agreed with Qatar Airways that the delivery of the initial A350-1000 will "now be planned early in the new year".
The first Qatar aircraft, the Rolls-Royce Trent XWB-powered MSN88 (pictured above in formation with an A350-900), conducted its maiden flight on 7 December.
Airbus has not disclosed the reasons for the schedule adjustment.
But it says it is "fully committed and focused to deliver the aircraft to Qatar Airways' full customer satisfaction".
Airbus states that the aircraft is undergoing "final preparatory steps" necessary for entry into service.
It has not given a specific date for the delivery, pointing out that this is the "airline's privilege".