Prices of wholesale gas have almost doubled during the past week, prompting fears about winter supplies to the UK.
Prices hit an eight month high of 80p a therm, sharply higher than last week's price of 43p, before dipping slightly.
Experts said fears the UK is about to face its coldest winter in 10 years and tight supplies had triggered the rise.
UK supplies are low as a pipeline from Europe is running at half capacity and shiploads of gas are being diverted to Spain and the US where prices are high.
Wood Mackenzie gas analyst Frank Harris told the Financial Times that operators could have made up to $14m more per cargo by selling to the US rather than the UK.
The UK is also facing the prospect of becoming a net importer of gas as supplies from the North Sea dwindle.
Such developments have prompted gas operators to draw down supplies from the country's biggest storage facility - the Rough offshore facility - that is normally filled now for use in January and February.
