Marathon Oil, the US energy group, warned yesterday that up to four large gas pipelines would have to be built to Britain in the next five years to avoid a dramatic shortfall in the supply of the fuel. The warning came as Marathon launched a five-month consultation into its proposed a nine hundred million dollar pipeline linking Norway's gas fields to south east of England. It follows claims by a leading energy consultant last month that a harsh winter could plunge parts of Britain into darkness by 2007 unless gas import and storage facilities were significantly improved.in the country William Hastings, managing director of Marathon's UK division, said that the falling gas production in the North Sea meant there would be a shortfall of about eight billion cubic feet of gas a day by 2010. The group's own pipeline, which is not expected to start operations until the end of 2005, would offset only about ten per cent of that shortfall. “There is an argument that at least three or four of these pipelines will have to be built to overcome this problem...Given that it takes at least three years to build a pipeline the debate on this issue has to start now,” he added. The government's energy review, commissioned by Tony Blair and published earlier this year, forecast that more than eighty percent of the country's gas will have to be imported by 2020. Mr Hastings said the most economic option would be to import gas from Norway rather than North Africa or the former Soviet Union, which are the other most likely sources. Marathon is conducting a series of meetings with gas companies to gain input into the design of its pipeline and commitments to use it. The outline proposal is to build a 675 kilometre-long pipe from the Brae/Miller field in the North Sea to Bacton in Suffolk, close to the landing point of the UK-Belgium interconnector. An additional 125 kilometre section would link the Heimdal field in the Norwegian part of the North Sea to Brae/Miller. The pipeline is expected to be the first in the North Sea to have open access to all gas shippers and will help alleviate bottlenecks at the St Fergus import terminal on the East coast of Scotland. Centrica, which owns British Gas, has given its support to the project and Dynegy, the US energy group, has separately said it is interested in new pipeline projects.