Airbus is offering U.S. airlines buying its A320 passenger jet extra-wide seats for obese passengers, leading to fatter profits, Airbus's aircraft interiors director says.

Airbus wants to make the most of the fact that its medium-range airliner is wider-bodied than the 737 from U.S. rival Boeing.

The company offers two 50-centimetre seats either side of the A320's single aisle instead of three 45cm seats either side.

"These seats are not meant just for overweight passengers," aircraft interiors director Zuzana Hrnkova told journalists on Thursday.

"Mothers with children may be ready to pay a little more in order to be able to keep their babies in their lap, and large football players may be interested," she said.

The company said that by charging extra for the wide seats, airlines could make US$3 million (AU$3.09 million) in extra profits over a 15-year period.

"Airlines asked us how they could create value with this wider cabin. We came up with this idea," Hrnkova said.

A third of the U.S. population is obese and obesity is on the rise in much of the world, including Europe and the Gulf.

Hrnkova said that so far only U.S. carriers had expressed an interest in the wide-seat configuration.