LONDON - OPEC on Monday said the world oil market shows signs of weakening in 2007 as economic growth slows, a problem the exporter group seeks to address through its decision last week to cut supply. In a monthly report, the group that pumps more than a third of the world's oil held its forecast for global demand growth at 1.3 million barrels per day and said a weakening US economy posed risks to the outlook."Risks for oil demand appear to be more weighed on the downside, given the dangers to global economic growth emanating from a visibly weakening US economy," the report by OPEC economists at the group's Vienna headquarters said.The report follows a deal last week by the Organization of the Petroleum Exporting Countries to cut supply by 500,000 barrels per day, or 2 percent, from February 1. Oil in New York has risen about $2 a barrel since the decision to stand at $63.18."This reduction has been scheduled to come into effect after the winter season, ensuring sufficient crude supplies during this strong demand period while addressing looming market imbalances for 2007," the report said.Forecasts for 2007, including a supply surge from non-OPEC countries of 1.8 million bpd -- the fastest growth in two decades -- point to "weakening fundamentals," it said.Rising supply from the Caspian, Africa and other regions would, if realised, reduce demand for OPEC oil to an average of 28.29 million bpd from 28.93 in 2006, OPEC said.The world economy will also grow more slowly. OPEC expects an expansion of 4.4 percent next year led by developing countries, down from 5.1 percent in 2006.Lower outputThe International Energy Agency, adviser to the industrialised world, said last week its own, slightly higher estimate of oil demand growth next year faced downside risks.But the agency, an adviser to 26 industrialised countries, urged OPEC to hold off on making a new supply reduction because existing supply curbs were already tightening the oil market.OPEC's decision last week to cut supply followed a deal it implemented in November to lower output by 1.2 million bpd to stem a slide in prices from July's all-time peak of $78.40.The report from OPEC added to estimates showing that members have yet to cut output by the full amount promised.OPEC's 10 members bound by supply targets, all except Iraq, lowered supply to 26.86 million bpd in November, OPEC's report said, citing secondary sources.That was down 552,000 bpd from October, but well above OPEC's target for November of 26.3 million bpd.A Reuters survey on December 6 found November supply from the 10 fell to 26.91 million bpd, down 730,000 bpd from October. Reuters