A briefing Saturday from engine maker CFM International suggests very big Airbus narrowbody sales success coming at the Paris Air Show. That outcome will build pressure on Boeing to change course and go for a new engine on its 737 instead of an all-new airplane.

CFM, a joint venture between GE and France's Snecma, is the sole source engine-maker for Boeing's 737 single-aisle jets. If Boeing does re-engine rather than going for an all-new jet design, it will almost certainly go with CFM exclusively.

The Airbus A320neo features new super-efficient engines. Chaker Chahrour, CFM executive vice president, said Saturday he believes Airbus will have 1,000 orders for the neo by year end.

Rumors are swirling in Paris that Airbus sales chief John Leahy could amass well over 600 orders by the end of the Air Show next week.

Chahrour (at right, CFM photo) is at the heart of every A320neo sales campaign, where the airlines have a parallel competition between CFM's new LEAP engine and Pratt & Whitney's geared turbofan.

So he's is in a position to know the strength of the sales wind pushing the neo forward.

Chahrour said CFM can be ready with an engine whatever Boeing decides.

"If they want a re-engine, we have one ready to go," said Chahrour, referring to a smaller version of the LEAP engine that's on the Airbus neo and also the forthcoming Chinese jet, the C919.

But if Boeing chooses an all-new design, CFM could offer a version of the LEAP with a larger fan than would fit under a 737 wing and one optimized around the new airframe.

"We want to do whatever is right for them," Charour said. "Whatever they decide to do, we are going to be there."