Shares in oil explorer Imperial Energy soared nearly 40 per cent to a record peak yesterday as the minnow disclosed that it has 3.4 billion barrels of reserves in Russia, as predicted by The Times.

Peter Levine, the chairman, added that 803 million barrels had been given a lucrative “2P” proven and probable tag, meaning a 50 per cent likelihood of recovery.

The “2P” figure is almost 150 per cent higher than the amount previously listed on Imperial’s books, and it is nearly double that held by Cairn Energy, the FTSE 100 explorer.

Mr Levine said: “We have answered some people’s doubts.”

Imperial had told investors to expect a “material” reserves upgrade in early March after a survey of 15 fields in West Siberia by American energy expert DeGolyer & MacNaughton.

But the details stunned analysts and Imperial’s shares raced up 353p to £12.45. The company floated three years ago on the Alternative Investment Market (AIM) at just 25p.

One analyst said: “I think the word one of our clients used is ‘astonishing’.”

Imperial’s market capitalisation is now £623 million, valuing Mr Levine’s 8 per cent stake at nearly £51 million.

He told The Times that the biggest challenge now facing Imperial was to dampen expectation and bring the fields to production.

Imperial has previously forecast that output from its four biggest fields will have reached 25,000 barrels a day by the end of 2008. This is likely to be updated when the group moves to the main market in April.

Mr Levine said: “This is the end of the beginning of the Imperial story. But we don’t want to get all cabaret, we have to build on this.”

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