Boeing said Monday that the long-expected 787 dreamliner is near completion and would embark on a first test flight in the last quarter of this year.

Boeing also pledged to deliver the first batch of 25 dreamliners in the third quarter of 2009.

The pledge came one month after the world's major aircraft maker postponed the jet's debut in commercial service until the third quarter of 2009. The latest delay was the third revision to its delivery schedule.

The 787 Dreamliner, the world's first mostly composite commercial airplane, rolled out of the hangar on July 8 last year with great fanfare, but it has failed to enter into commercial service due to repeated delays in deliveries.

To defuse disappointment and confusion that might be resulted from such delays, Boeing invited a group of domestic and foreign reporters to the dreamliner's assembly site in Everett, Seattle, on Monday to take a close look at production.

The program has overcome parts shortages and hiccups in its new, decentralized manufacturing model and is making steady progress toward the airliner's much-delayed first flight, said Patrick Shanahan, General Manager of the program.

The jetliners "is on track" for a June "power on" milestone, and subsequent planes are arriving at the final assembly floor in better and better shape, he added.

Most of 787's major parts are outsourced around the world before they are shipped to Everett for final assembly.

Since October, Boeing has announced three major 787 delays, but Boeing CEO James McNerney has said Boeing finally has a revised schedule that it can meet -- first flight in the fourth quarter, initial deliveries pushed back from May until the third quarter of 2009, and 25 Dreamliners delivered by the end of 2009 rather than 112 as originally planned.

The company said in a press release that despite the delays, the 787 market "remains strong." Since Boeing launched the program in 2004, 58 customers have placed orders for 896 airplanes from six continents of the world valued at 151 billion U.S. dollars, making this the most successful launch of a new commercial airplane in Boeing's history, according to the release.

But failure to deliver the airplanes on time will likely cost the company billions of dollars in additional costs and penalties.

Described as environment-friendly, Boeing said the 787 will use 20 percent less fuel per passenger than similarly sized airplanes, produce fewer carbon emission, and have quieter takeoffs and landings.

The passengers will have more humid air and larger windows in the cabin, as well as softer lighting automatically adjusting with the time of day or night, the company said.