ITM intends to unveil a Ford Focus car and a device to refuel it with hydrogen, which if successful could go in anyone's garage, by the end of 2007.

A car with the technology would cost around 2,000 to 3,000 pounds more than its petrol equivalent, Chief Executive Jim Heathcote said, assuming it was mass produced.

Hydrogen cars would reduce carbon emissions to zero but the stumbling block is getting hydrogen to vehicles without the need to refit filling stations.

"When we have the prototype devices ready we hope to publicly launch the refuelling system and car together with the intention of attracting attention from the automotive industry," Heathcote said in an interview on Tuesday.

ITM has already developed and tested a Ford Focus car which can run on hydrogen for 25 miles on a fuel cell which it has developed, before switching to petrol. Ford is not involved in the development.

ITM previously said it would show off the bi-fuel car this summer, but Heathcote said the later demonstration will also show how it can be refuelled and will contain technology closer to what might be mass-produced.

Shares in ITM were down 5.5 percent by 11:43 a.m. as it gave full-year results in line with market expectations and hit technical milestones, analysts said. But some investors had been hoping for new contract wins, a trader said.

ITM's devices for refuelling in the home use water and electricity to create hydrogen using its electrolysers.

This solves the "chicken and egg problem" of hydrogen-fuelled cars; namely, that manufacturers are reluctant to develop hydrogen vehicles if there is not the infrastructure to refuel them, Heathcote said.

"I hope that when we demonstrate the vehicle all of the people working on fuel cell technology in hydrogen cars will see you don't have to wait 10 or 20 years to build the hydrogen infrastructure," he said.

"The manufacturers can supply you with a refuelling kit with the car and you can do it at home."

The refuelling tanks ITM is currently hand-making cost between 3,000 and 4,000 pounds each but these prices would be much lower if they were mass produced, he said.

The cost of running a car on hydrogen is estimated to be slightly cheaper than running it on petrol at current prices, Heathcote said. Owners should also have to pay lower road tax and congestion charges, he said.

ITM is also working on household solar panels which make electricity to produce hydrogen that can then be used in the car or for household heating.

"This is in early stages but it could mean you have a non-polluting household," Heathcote said.