Nokia is the world's leading mobile manufacturer

The firm committed to fuel cells eight months ago but has now said the sector is "not yet mature".

Nokia's Matti Naskali said the firm had not abandoned the technology, saying: "Fuel-cell technology is promising and Nokia continues to follow it closely."

A fuel cell can be re-filled like a lighter, rather than charged.

A fuel cell would also allow longer talk and standby times and increased power for power-hungry applications such as video.

In June 2004, Tero Ojanpera, head of Nokia's research centre, demonstrated a headset that was powered by a small amount of methanol.

The fuel cell combined the methanol with air to produce power.

At that time, Mr Ojanpera said the technology was "reasonably mature" and he predicted that it would take less than two years to bring products to market.

But Mr Naskali, research manager at Nokia Japan, said several issues with the technology had dented the firm's enthusiasm.

Current air transportation rules prohibit the carrying of methanol, which is flammable, on an aircraft without special packaging.