Aircraft manufacturing giants Boeing and GE Aviation yesterday announced they will join Continental Airlines in undertaking a demonstration flight using biofuels.

The test flight is scheduled for the first half of next year and, if successful, will make Continental the first major US carrier to use biofuels in flight.

Mark Moran, vice president of operations at Continental Airlines, said the aim of the test flight was to identify "sustainable" biofuels that could be used by the aviation industry. "Exploring sustainable biofuels is a logical and exciting new step in our environmental commitment," he added.

The move follows Virgin Atlantic's inaugural flight last month of a Boeing 747 using a blend of 80 per cent normal jet fuel and 20 per cent biofuel made from coconut oil and babassu oil in one of its four main fuel tanks.

The move was dismissed as a "publicity stunt" by some environmental groups, but Virgin insisted it was an important step in the development of more environmentally sustainable aviation fuels. The company is now investigating the commercial viability of developing aviation fuels from algae.