LONDON - Small and medium-sized British businesses could cut their energy costs by up to 30 percent a year but are unaware of the true potential for savings, a survey by the Carbon Trust shows.

The Carbon Trust, which advises the UK government, polled 700 small and medium-sized enterprises (SMEs) which spend between 50,000 pounds and 3 million pounds a year on energy.

It found that UK businesses could reduce their collective energy costs by more than 3 billion pounds by controlling the way employees use energy, controlling lighting and heating and investing in the building's equipment and infrastructure.

On Wednesday, the Trust kicked off a drive to cut the energy use, typically by 20 to 30 percent, of companies who spend 50,000 to 3 million pounds a year on energy bills, through free expert on-site advice, action plans, as well as interest-free loans.

The SME community in the UK is huge. There are tens of thousands of companies with energy bills over 50k which would qualify for a survey but they aren't doing it, Hugh Jones, Carbon Trust's director of solutions, told Reuters.

The survey showed that 49 percent of respondents were worried about volatile energy costs in 2010. Sectors with the greatest concerns were construction, manufacturing and hospitality.

Some of the smaller organizations, particularly in the service industry, still haven't understood the opportunity in (cutting energy use), Jones said.

One in seven respondents in the survey said there was nobody in charge of the company's energy management, yet a third of companies with over 50 staff said improving their green credentials was a top priority for 2010.

As we emerge from recession, companies with a good base of energy efficient behavior -- their customers will like it, employees will be more motivated and their bottom line will be helped, Jones said.

(Reporting by Nina Chestney; Editing by William Hardy)