ABERDEEN-headquartered Faroe Petroleum's shares surged yesterday after drilling revealed the presence of oil at a Norwegian Sea exploration well.

Shares in Faroe, which is focused on exploration, appraisal, and production opportunities in the Atlantic Margin, the North Sea, and Norway, jumped by 12.5p or 9% to 149p. This raised Faroe's stock market worth by £26.5 million to £316.5m.

Faroe said the Cooper well in the Norwegian Sea, in which it has a 30% interest, had been drilled to a depth of 5330 metres below sea level and had "encountered hydrocarbons in Middle Jurassic Garn formation".

Based on preliminary results, the joint venture involved in the well, which is operated by Scottish Gas owner Centrica with its 40% interest and includes Suncor of Canada with a 30% interest, had decided to perform a "drill stem test" of this Garn formation "to evaluate the likely productivity of the reservoir".

Faroe chief executive Graham Stewart said: "We are encouraged by the preliminary results for the Cooper well. However, we need to await the results of the flow-testing programme to establish likely productivity of the hydrocarbons and the commercial potential and size of the discovered resource."

He expects results from the North Uist exploration well west of Shetland, in which Faroe has a 6.3% interest, within weeks.

Mr Stewart said: "This continues to be an exciting period for Faroe, with operations ongoing on the BP-operated North Uist exploration well west of Shetland, where a number of technical issues have delayed the drilling operations. Results are expected in the coming weeks together with the test results for the Cooper well."

Faroe also said it had doubled its bank credit facility to $250 million (£160m) to support growth. Its banking facilities are with BNP Paribas, Lloyds TSB, Commonwealth Bank of Australia, DNB Bank, Royal Bank of Scotland, SEB, and SR Bank.

Faroe had cash of about £103m at June 30. Citing cash flow from producing assets including the Blane, Brage, Njord, Ringhorne East and Jotun fields, it said it was "well-financed" for forward work programmes.

Iain Lanaghan, finance director, said: "Alongside our robust production cash flows, this available credit provides us with greater funding capacity to support the development of the group in our core areas, both in terms of organic and acquisition growth."