FRENCH aerospace giant Airbus's new long-haul carrier, the A350, should make its maiden flight at the end of next week unless bad weather or unexpected problems crop up, sources say.

"The final ground trials went very well. Weather permitting, it should fly next week," said one of the sources, tipping a Saturday flight.

Pascal Verneau, the chief engineer for flight tests, said "personally, I am hoping the first flight takes place before Bourget."

The Paris Air Show at Le Bourget airport opens on Monday, June 17.

It comes as the plane manufacturer revealed a revised seating option for the A380 which could fit up to 600 people.

Verneau said a couple days of engine testing plus two tests reaching takeoff speed remain.

The maiden flight should last around four hours, he added, with the A350 flying over the Pyrenees mountains or the Brittany region depending on the weather conditions.

Airbus officials downplayed the possibility the A350 could make an appearance at the Paris Air Show.

Airbus hopes the 314-seater will compete with Boeing's 787 Dreamliner by being both lighter and more fuel-efficient than previous models.

The first deliveries of A350s to airlines are scheduled for the end of 2014.

So far, Airbus has received orders for 616 of the aircraft.