Pratt & Whitney's geared turbofan engine, which has secured hundreds of orders to power Airbus's upgraded A320 narrowbody, could be scaled up for use on larger widebody airplanes, its chief executive said on Sunday.

Pratt, a unit of United Technologies Corp , is looking to win more engine orders at this week's Paris airshow.

Chief Executive David Hess said he expected deals for the upgraded A320 this week. Orders for the neo you're going to see are astounding, he told Reuters in an interview a day before the official start of the Paris airshow.

Hess said both Airbus EADS and Boeing Co see potential widebody applications for the geared turbofan engine, which promises double-digit percentage improvement in fuel savings and emissions.

It is not just a narrowbody engine; it is an engine that we see having an application for large commercial transports of other sizes, Hess said.

Widebody use may not be a near-term opportunity for Airbus because they have got the widebody product strategy set, but maybe more for Boeing as they start to look at potential replacements for 777, Hess said.

Securing a position on a widebody plane model would potentially see a return of Pratt as a standalone supplier to the market for long-range, widebody airplanes with about 250 to 350 seats. Aerospace analysts have said the Airbus A320neo placement brought Pratt back into the narrowbody plane market in a significant way.

Pratt's key rival for A320neo engine orders is the CFM International venture between General Electric of the United States and Safran of France. CFM engines power Boeing's 737 narrowbody and some Airbus A320s.

Hess said he believed Pratt would have a better chance to win a spot on Boeing's 737 should that narrowbody plane be redesigned as opposed to re-engined. Boeing said on Sunday it may have a decision on that plane model by the end of the year.

Hess also said the geared turbofan was gaining a following among major airlines. For example, he said Delta Air Lines Inc , which sent a request to several plane makers late last year for proposals to deliver up to 200 narrowbody planes to replace aging models, is positive on the engine but he added it is not clear what their timing is on a potential airplane order.

Pratt's geared turbofan has more than 1,200 engines on order, including options, for the Bombardier CSeries, Mitsubishi Regional Jet and Airbus A320neo family of aircraft.

Pratt also builds the engine used on the early production models of the F-35 Joint Strike Fighter being built by defense contractor Lockheed Martin Corp .

(Reporting by Tim Hepher and Karen Jacobs; Editing by Diane Craft)