Cargolux is preparing to source alternative aircraft capacity should the dispute over delivery of its new Boeing 747-8 freighters fail to reach a quick conclusion.
The airline said it opted to "reject" the first two 747-8Fs which had been due for delivery on 19 and 21 September.
Cargolux said it has "unresolved contractual issues" with Boeing regarding the aircraft, and made the decision at a board of directors meeting on 16 September.
Financing of the jets, secured through JP Morgan, has been "put on hold", it added.
"In the event that the issues cannot be resolved in a timely manner, Cargolux will source alternative capacity to fully meet customer demand and expectations ahead of the traditional high season," said the airline.
Cargolux has assembled a new board of directors following the just-completed acquisition by Qatar Airways of a 35% shareholding in the Luxembourg-based freight specialist.