PARIS, June 19 (Reuters) - China's Comac could build a larger version of its C919 aircraft in the early 2020s to tempt airlines away from dominant global planemakers Airbus and Boeing, the head of Irish low-cost carrier Ryanair said.
The first C919 model, carrying 174 passengers in a high-density configuration, is due to reach Chinese customers from 2016.
A second model with up to 200 passengers could interest airlines outside China, however, Michael O'Leary said at the Paris Airshow on Wednesday.
"The sweet spot is not 174 but as close to 199 or 200 that you can get," said O'Leary.
Ryanair, which has an all-Boeing 737 fleet, signed a design agreement with Comac two years ago to help produce a rival jet. The Irish carrier does not operate any of European planemaker Airbus' A320-family of single-aisle jets.
The CEO said the first C919 version would quickly become "outdated" but added that Ryanair was working with the Chinese company to develop a larger model as soon as possible.
Comac could benefit from new engine technology to be used on the latest more fuel-efficient versions of Airbus and Boeing's best-selling single-aisle planes, O'Leary added.
If delivered by the early 2020s, the plane would "put pressure on Boeing and Airbus" and benefit airlines, he said.
"That will give us three credible suppliers by the early 2020s," he said.
Ryanair earlier on Wednesday signed a contract to buy 175 Boeing 737-800 jets, worth $15.6 billion at list prices, and said it could order 200 or more Boeing 737 MAX aircraft by the end of the year.