Boeing Corp. has started work on a stretched-out version of its popular 787 Dreamliner jet.

It announced the formal launch of its 787-10 program at the Paris Air Show on Tuesday and said it already has commitments from several customers, including United Airlines.

The original 787 can seat between 210 and 250 passengers. Boeing is already working on a longer version, the 787-9, that would hold between 250 and 290 passengers, while the 7870-10 would seat between 300 and 330.

The air show is a platform for the race for sales between Boeing and its European rival Airbus, which is hoping that the event sparks interest in the A350, its long-haul wide-body rival to the 787.