THE HAGUE: A Boeing 747, one of four engines powered by a 50-percent biokerosene mix, circled the Netherlands for an hour on Monday for what airline KLM called the world's first passenger flight using biofuel.

"This is technically feasible. We have demonstrated that it is possible," KLM chief executive officer Peter Hartman said after the flight, which took off and landed at Schiphol airport near Amsterdam.

"Government, industry and society at large must now join forces to ensure that we quickly gain access to a continuous supply of biofuel."

The flight had about 40 people on board, including Hartman, Economic Affairs Minister Maria van der Hoeven, the director of nature group WWF in the Netherlands, Johan van de Gronden, and a handful of journalists.

KLM spokeswoman Monique Matze told AFP that of the Boeing's four engines, one was powered by a mix of 50 percent sustainable kerosene and 50 percent normal fuel. The biofuel was manufactured from the camelina plant, sourced from a biotechnology company based in Seattle in the United States.

The test flight was also the first of any kind in Europe powered partly by sustainable biofuel, according to KLM.

"Of course, we compensated the footprint of transporting the fuel from the United States to here," added Matze, citing ongoing projects to reduce CO2 emissions.

KLM said its quest for biokerosene was conditional on forests, food and water sources not being jeopardised.

Matze said the company "dare not name any targets" for switching to biofuel for its commercial flights, saying "the difficulty now is the availability of biofuels."

Monday's flight, she said, was "the first step towards ensuring clean and sustainable air transport."