Airbus hopes the plane, hit by production delays, will become the centrepiece of efforts to develop the next generation of cleaner fuel at a time when the aviation industry is under pressure over the impact of emissions on the climate.

Sebastien Remy, head of Airbus SAS's alternative fuel programme, said the GTL used on Friday was no cleaner in CO2 (carbon dioxide) terms than regular fuel but it had local air quality benefits because it produces no sulphur.

He said the take-off showed Airbus was "preparing for (the) emergence of a wider slate of synthetic fuels".

By 2025, he said, a quarter of jet fuel could be some form of alternative fuel.

The fuel used, a mix of 60 percent standard jet kerosene and 40 percent GTL, was used in one of the A380's four engines.

The GTL was made in Malaysia from natural gas and, as such, is a fossil fuel not a biofuel, which are made from renewable resources.

But Remy said GTL was the first step to developing BTL (biomass-to-liquid) fuel, which can use anything from wood chips to crops.

He wants to avoid competing with food crops, and said the research emphasis was on growing biomass where food crops are not grown, such as arid regions.

Eventually, algae could be one source.

The A380's take-off from the planemaker's Filton base was watched by reporters and hundreds of Airbus workers. It landed at Toulouse, southwest France, after a three-hour test flight.

The first A380 to carry passengers entered service with Singapore Airlines late last year after an 18-month delay caused by difficulties in installing the mammoth aircraft's wiring.

Anxious to focus on what it describes as the aircraft's environmental benefits, in terms of the amount of fuel consumed per passenger, Airbus has already rebranded the A380 the "gentle green giant," and softened its marketing presentations.

Airbus staged Friday's display weeks before British billionaire Richard Branson's Virgin Group planned to conduct a test jet flight on renewable fuels on a Boeing 747.

The company has said it plans a flight in early 2008 and the debut had been expected in February. The A380 was designed to break the 747's 30-year monopoly on very large passengers jets.

He said the first commercial use of GTL could be in 2009 by Qatar Airways after it has taken delivery of its first A380.

Qatar has the world's third-largest reserves of natural gas and Shell and Qatar Petroleum are building a GTL plant, called Pearl, which is due to be fully operational by 2011.

Qatar Airways's Stephen Vella said the airline wanted to use a 50 percent GTL blend from 2009 but only on a limited scale until Pearl is complete.