Boeing is delaying delivery of its first new-generation 787 Dreamliner aircraft until early 2011.
Japan's All Nippon Airways was due to take delivery of the aircraft at the end of this year.
The 787 project has already been delayed for more than two years, following a series of hitches.
Boeing said on Friday the setback was due to the availability of a Rolls-Royce engine needed for the final phases of flight testing.
The US company said that it now expected All Nippon to take delivery of the aircraft in the middle of the first quarter of 2011.
The 787, being built in Seattle, is Boeing's most sophisticated plane yet. The company claims the carbon-composite aircraft will be lighter, faster and emit less CO2 than similar-sized planes currently flying.
However, delays on such huge industrial programmes are not uncommon. Development of Airbus' A380 super-jumbo was dogged by problems, plunging the manufacturer into heavy losses and forcing a clear-out of management.
ANA has ordered 55 Dreamliners, eight of which Boeing had promised to deliver by the end of March.
"Given the success of the flight test programme so far, it is regrettable to hear of the delay," said an All Nippon spokeswoman.
A spokesman for Rolls-Royce said: "We have been informed by Boeing that the currently planned dates for Trent 1000 engine deliveries will now not support their latest flight test programme requirements.
"We are working closely with Boeing to expedite delivery in support of their programme schedule.
"Rolls-Royce confirms that the engine availability issue is unrelated to the test bed event which occurred earlier this month."
On 2 August a Rolls Trent 1000, which will power the 787, failed during testing.
The company's spokesman declined to give specific details of the incident. But the Bloomberg news agency reported at the time that a turbine blew up and the test facility was closed temporarily.
It was unclear if the 787 delay would mean Boeing having to reschedule deliveries to other airlines.
In July, Australia's Qantas brought forward its 787 delivery schedule, saying it would receive the first 50 of the aircraft it has on order in mid-2012.
A spokesman said on Friday: "We are seeking more clarification from Boeing."
Qantas, Air New Zealand, and Air India have said they will seek compensation running into million of dollars for previous 787 delays.
However, analysts believe any compensation deals would be settled through aircraft discounts and maintenance agreements rather than cash payments.
The 787 made its maiden flight in December 2009 and was a star feature at July's international airshow at Farnborough in the UK.