Companies looking to do their part in the fight to reduce climate change have been advised to focus on cutting their IT energy use.

According to Manchester-based green IT firm Tranquil PC, the increase of computer users in UK firms as the country switches to a service economy means that using energy efficient machine can have a big impact.

"In the early days... there would have been a very limited number of computers in the office because they would have been quite expensive, said Tranquil PC director David Thompson.

"Nowadays... in the office everybody has a computer in front of them."

He added that "the sheer number of machines does contribute considerably, not just to the green aspect, but also to power costs as well."

Companies were advised either to reduce the number of machines they use or upgrade their existing stock to models which use up less energy.

This follows claims from the government-financed programme Envirowise that environmentally-friendly policies can save companies money as well as the planet.

Director of the organisation Dr Martin Gibson told the BBC earlier this year that green changes can save "up to £250 per employee in office-based companies or as much as £1,000 per employee for manufacturers".