The Boeing Co has confirmed a fourth delay for the prestigious 787 Dreamliner programme saying the bestselling aircraft won't reach customers until the first quarter of 2010, almost two years behind schedule.

The Dreamliner's first flight will not take place until next year's second quarter. The Chicago-headquartered company attributed fresh delays to a eight-week long strike by the company's machinists and also to problems faced in replacing fasteners.

Along with the revised schedule the company also announced a reorganization of its commercial aircraft set up, shifting managers and also creating a new position to monitor operations by suppliers, who have been held responsible for previous delays.

Pat Shanahan, brought in to reorganize the 787 programme last year, is now in charge of all commercial planes. Scott Fancher will handle the Dreamliner programme reporting directly to Shanahan, Boeing said.

The company also appointed Ray Conner, 53, a 30-year Boeing veteran, as in charge of supplier-management operations.

The 787 was due to enter service with launch customer All Nippon Airways Co. in May this year.

Boeing has lost 60 per cent of its market value since the first 787 delay was announced in October 2007.

Meanwhile all the bad news is not translating into bad sales for the aircraft as the company updated its weekly online backlog tally to add another 15 orders for the 787. This fresh order brings the total count to 910 Dreamliners, valued at more than $157 billion.

Boeing is still working out revised delivery schedules for customers and said it will disclose the financial impact of delays later.