Oil is leaking from a pipeline to a North Sea oil platform off the Scottish coast, dpa quoted the operating company Royal Dutch Shell as saying on Saturday. "We can confirm we are managing an oil leak in a flow line that serves the Shell-operated Gannet Alpha platform," a company spokesman said. The spokesman could not say how much oil had been spilt from the pipeline around 180 kilometres from Aberdeen off the Scottish coast. A remote-controlled device had checked for the leak under the sea surface after sheen from an oil slick had been detected, he added. "We have stemmed the leak significantly and we are taking further measures to isolate it. The subsea well has been shut in, and the flow line is being de-pressurized," the spokesman said. The Department of Energy and Climate Change said it has responded to the incident and that it understood from Shell that a "finite amount of oil" would be released. US company Exxon co-owns the field through its European subsidiary Esso. Earlier this month, a UN study on years of spills in Ogoniland in the Niger Delta found the clean-up could take 30 years and cost a billion dollars. Shell has accepted liability for two spills.