According to Reuters, Airbus is seeking airline support for a new 400-seat version of the A350 as competition escalates over two-engine aircraft.

After talking up the possibility of a new member of its A350 family, Airbus has swung into an active pre-marketing phase as it responds to a recent upgrade in the competing Boeing 777.

While Boeing has scored successes in the Gulf with the 406-seat 777-9, Airbus is expected to aim its design at airlines that do not always require the performance needed for extreme Gulf conditions.

"It would have similar capacity and range (as the 777-9) and substantially lower seat-mile costs," Airbus sales chief John Leahy said in an interview. "We are showing it to airlines right now."

Sources say it is being pre-marketed with a surprise new identity, the A350-8000, though a final decision has yet to be taken.

Two airlines whose feedback could be decisive in whether Airbus launches the new jet are Singapore Airlines and British Airways. Both airlines declined to comment.