Boeing has delayed the first flight of the 787 by three months, to the end of the second quarter, to provide additional time to complete assembly of the first aircraft.

Deliveries are now expected to begin in early 2009, rather than late 2008. Boeing will hold a conference call later today to discuss the delay. The company had planned to deliver 109 aircraft by the end of 2009.

In a statement, Boeing Commercial Airplanes chief executive Scott Carson says "we continue to be challenged by start-up issues in our factory and in our extended global supply chain".

The rate at which jobs are being completed on Dreamliner One has not improved sufficiently to maintain the current schedule, he says.

"Our revised schedule is based upon updated assessments from the 787 management of the progress we have made and the lessons we have learned to date," Carson says. "This includes our experience on the factory floor completing production work on the airplane that was originally intended to be done by our suppliers."

Boeing says it will work will customers and suppliers to assess the impact of the delay on the flight test programme and entry into service. this will include an assessment of supplier progress in delivering more complete assemblies for subsequent aircraft.

For more on the 787 delays, read Flightblogger's latest update.