By Alison Gee BBC World Business Report

One of Japan's largest car makers, Nissan, has brought forward plans to sell cars which don't run on traditional petrol or gas.

It is hoping to put a new fuel cell vehicle on the market as soon as next year.

This comes at a time when an increasing number of governments are encouraging the auto industry to develop environmentally friendly fuels.

Last week Honda announced it would begin leasing hydrogen powered cars in California by the end of this year.

Changing attitudes

California is an important market for this technology. Earlier this month the state's governor, Gray Davis, signed the first bill in the US designed to force car makers to find ways of reducing greenhouse gas emissions from their vehicles.

Although attitudes like this are encouraging the development of new fuels, it will be many years before they are available to the average car owner.

Graeme Maxton from the auto consultancy Autopolis said initially the biggest market is going to be in buses and taxis and small fleets of vehicles.

"The big problem of course is that if you want to refill your car with hydrogen there simply aren't the filling stations around right now to do that," he said.

"So the first area that these vehicles will be targeted at are fleets because you have one central filling point rather than having to have a whole network of fuel stations."

Almost pollution free

Nissan originally planned to launch its fuel cell car in 2005, but the vehicle could now be on limited sale within a year.

Instead of using traditional petrol or gas it uses hydrogen.

When combined with oxygen this generates energy, which when converted into electricity is used to power the car.

The big attraction is that it is almost pollution free - the by-products are heat and water.