Airbus said on Tuesday that its A350-1000 widebody aircraft had received certification from US and European aviation authorities, clearing the way for its delivery and entry into service.
A longer version of the Airbus A350-900, the twin-engine plane can accommodate an extra 40 people, taking its total capacity to 366 people.
Equipped with stronger engines as well, Airbus said the A350-1000 "is perfectly tailored for some of the busiest long-haul routes".
Airbus said 11 customers have already ordered 122 of the aircraft, and it hopes to make the first delivery to Qatar Airways by the end of the year.
The plane's main competitor is the Boeing 777-300, in particular the larger 777-300ER version.
Airbus has calculated the operating costs of its A350 will be about a quarter less than for its American rival, which first took flight in the 1990s.