Around four fifths of manufacturers have seen their fuel bills rocket at least 30 percent in the last year, an industry survey showed on Monday.

The Engineering Employers' Federation said 92 percent of the 232 companies it polled in its annual energy survey said their energy costs went up in the last year.

Some 80 percent said their gas bills had gone up at least 30 percent, while 76 percent reported a similar increase in their electricity bills. That compares with 54 percent and 53 percent respectively in the 2005 survey.

Dwindling gas supplies from Britain's North Sea fields have pushed up prices and the problem has been compounded by limited capacity to pump in supplies from Europe.

The EEF said around a third of firms tried to cut their fuel bills by switching supplier. However, it also said a growing number of firms had opted to sign up for longer contracts with utility firms to protect themselves from further price hikes.

Wholesale gas prices have recently started easing on the prospect of new supply pipelines from Norway and the Netherlands coming on stream this winter.

But the EEF said manufacturers would not benefit from those price falls until next year.

Despite recent falls, the price of energy remains higher than it was this time last year and there is little prospect of industry seeing any benefit for the foreseeable future, said EEF Director General Martin Temple.

The EEF said some firms had said they would be forced to cut jobs this winter as margins are squeezed by high energy prices.