Aircraft engine manufacturer CFM International is discussing with Aviation Industry Corporation of China building a final assembly line in China for the Leap-1C engine, the initial engine of the C919.

"The discussion has not finished yet, but we still have a lot of time to get to that point," said Chaker A Chahrour, executive vice-president of CFM International, a joint venture between the French Safran Group and General Electric from the United States.

The engine manufacturer still has three years before delivery of the first engine to its Chinese client and will test the first engine for the C919 in September, according to its schedule.

CFM International has also pledged to boost the overhaul capability for the Leap-1C in its joint venture with Air China Ltd in Chengdu, Sichuan province, said Xiang Weiming, general manager of GE Aviation in China.

"But this will be decided by the C919's delivery scale," Xiang said.

The manufacturer's Leap engines also will be supplied to Airbus 320neo and Boeing 737max aircraft.

It will begin producing Leap engines in 2016, and plans an annual output of 1,700 engines by 2020.