Seattle/New York - US airplane manufacturer Boeing again postponed the test flight of its new flagbearer, the 787 Dreamliner, the financial news television channel CNBC reported Tuesday, although Boeing said such a decision had not been made.

After an almost-two-month-long machinists' strike that just ended, the test flight of this long-haul plane will not take place before the end of the year, as Boeing had planned, according to the report.

A Boeing spokesman stressed, however, that there had been no such decision.

If the company continues to delay its plans, Boeing could face billions of dollars in fines and lost sales.

Delivery of the first Dreamliners to clients had been scheduled for the third quarter of 2009, over a year later than originally planned. Since then, there has been speculation as to a new deadline for 2010.

New problems arose during the production phase, financial news agency Bloomberg reported. A Boeing spokeswoman confirmed this, although she did not confirm plans for further delays.

Despite the problems, the Boeing 787 is already the most successful plane in the company's history, with some 900 orders.

Earlier Tuesday, Boeing said the global air freight business is set to grow at an annual average of 5.8 per cent in the next two decades, despite the uncertainty that is shrouding the global economy at a time of crisis.

International air cargo traffic is expected to increase three-fold by 2027.

The global freight fleet is set to rise in the next 20 years from the current 1,950 planes to 3,890 units, Boeing said.

The trend points to bigger planes: in 2027, 35 per cent of all cargo carriers are set to be of the Boeing 747 and 777 types, compared to only 26 per cent nowadays. The EADS-subsidiary Airbus is represented in this category with the models A330 and A340.