LONDON - The world's first commercial passenger flight powered by a fuel made from natural gas completed late on Monday a six-hour journey from London to Qatar, one of the biggest producers of natural gas.

Today's flight opens the door to an alternative to oil-based aviation fuel, Malcolm Brinded, Royal Dutch Shell's executive director upstream international, said in a statement late on Monday.

We are now well on the way to launching GTL on a world scale for the first time, Brinded said.

Shell developed and produced the 50-50 blend of synthetic Gas to Liquids (GTL) kerosene and conventional oil-based kerosene fuel used in Qatar Airways' Airbus A340-800 aircraft powered by a Rolls-Royce Trent 556 engine.

This is a major breakthrough which brings us closer to a world where fuels made from feedstocks such as wood-chip waste and other biomass is available for commercial aviation, Rainer Ohler, a spokesman for Airbus, said.

Airbus predicts that in 2030, up to 30 percent of jet fuel will be alternative.

The fuel burned with lower sulphur dioxide and particulate emissions, which should help improve local air quality at busy airports.

Qatar will become the world's leading producer of GTL kerosene when it is put into commercial production from 2012. It is already the world's top exporter of liquefied natural gas.

Qatar Petroleum and Shell are building the Pearl GTL plant, which has an annual capacity of around one million tons -- enough to carry 250 passengers around the world 4,000 times when used in a 50 percent blend to make GTL jet fuel.

Commercial aviation is one of the exciting new markets that this opens up, helping us maximize the value from our natural resources, said Qatari Deputy Prime Minister and Minister of Energy and Industry Abdulla bin Hamad Al-Attiyah.

Energy