Middle East Airlines has asked Airbus and Boeing to submit offers for the A350 XWB and 787 as part of the airline's long-haul fleet planning.
MEA's proposal covers five firm aircraft and three options, but delivery would not be until around 2017.
The Beirut-based carrier has just started introducing four new A330-200s, part of an expansion and renewal programme.
Speaking to Flight International at the Arab Air Carriers Organisation conference in Tunis, MEA chief Mohamad El-Hout said expectations of an increase in short- and medium-haul traffic could result in the airline switching these A330s to medium-haul routes. "The A330s would replace some of the A321s," he added.
El-Hout said that the airline could make a decision between the 787 and A350 by the end of 2009, or the beginning of 2010.