Reuters/Geneva

Germany's Lufthansa has stepped up to become the first airline due to take delivery of a revamped Airbus passenger jet, after Qatar Airways voiced uncertainty over the technical performance of its Pratt & Whitney engines.

Confirming a news report, the German flag carrier said it would take delivery of the upgraded A320 earlier than expected.

"We expect to get our first A320neo in December and that would technically make us the launch operator," a spokesman said on Thursday.

The A320neo, seen as a key profit driver for the European planemaker and its suppliers in coming years, is getting its final touches after winning safety approval in late November.

Until now, Qatar Airways had been first in line to operate the latest version of Airbus's best-selling jetliner.

But Chief Executive Akbar al-Baker opened up the prospect of a delay to the Gulf carrier's first A320neo at a news conference on Wednesday, saying that while he still expected delivery this year, any delay would be Pratt & Whitney's fault.

Both Pratt & Whitney and Airbus said they would meet an end-year target for first delivery, without saying which carrier would receive the jet.

"Along with Airbus, we are continuing to work with early customers on the first delivery of the aircraft. The team is on track to deliver the first A320neo this year," a spokeswoman for Pratt & Whitney said on Wednesday.

The switch emerged as Pratt & Whitney's parent United Technologies prepared to hold a regular investor meeting. Its shares slipped 0.4% in a slightly stronger market.

The A320neo offers 15% lower fuel consumption thanks mainly to a choice of next-generation engines from Pratt & Whitney or CFM International, a joint venture of General Electric and France's Safran.

Boeing rolled out its own upgraded competitor, the CFM-powered 737 MAX, earlier this week.

Pratt & Whitney's Geared Turbofan engine marks a break with recent jet engine architecture and a major new corporate investment after years in the doldrums in civil aerospace. But the engine has suffered teething problems during testing.

In May, Airbus said it was suspending some flight tests to allow the US company to modify a component known as a snap ring, a part used to keep a seal in place.

Aviation Week, which first reported the switch in the delivery line-up, said Qatar Airways had refused to take the jet as planned because of potentially costly operational restrictions on the initial batch of engines. The airline declined further comment.

Any performance issues would not affect the safety of the aircraft, but are likely to grab attention as Pratt & Whitney bets on a recovery in its once-dominant civil engine business.