Boeing Co said on Friday it now expects delivery of the first 787 Dreamliner in the middle of the first quarter 2011, owing to a delay in engine availability.

The delivery date revision of the long-delayed carbon-composite Dreamliner follows an assessment of the availability of an engine needed for the final phases of flight tests this fall, Boeing said.

Boeing said it is working closely with Rolls-Royce Group PLC to expedite engine availability. The company said the delay in engine availability has extended the delivery date estimate to mid-first quarter 2011.

Boeing had said last month that due to a series of issues, the first delivery of the 787 could be pushed a few weeks into 2011.

Boeing's launch customer, Tokyo-based All Nippon Airways <9202.T>, said it was seeking to clarify with the aircraft maker as soon as possible when it will get delivery of the second 787.

ANA has ordered 55 of Boeing's latest jetliner, eight of which the U.S. company 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 ANA spokeswoman Megumi Tezuka.

The Japanese carrier did not include revenue from the 787 in its business plan this year so there will be no change to its profit outlook for the year ending March 31, Tezuka added.

A spokesman for Australia's Qantas Airways said it was too early to say what the impact would be.

We are seeking more clarification from Boeing, the spokesman said.

Qantas in July brought forward its 787 delivery schedule, saying it would receive the first 50 of the aircraft it has on order in mid-2012.

Boeing said on Friday the schedule revision will not affect the company's financial outlook.

Despite the delay, Boeing said the flight testing across the test fleet continues as planned.

(Reporting by Sakthi Prasad in Bangalore and Chang-Ran Kim in Tokyo; Editing by Muralikumar Anantharaman and Tim Kelly)