By 1554 GMT yesterday, U.S. light sweet crude was trading 71 cents lower at $63.50, while London Brent crude fell 58 cents to $62.14. U.S. demand for heating fuels was expected to be about 34 percent below normal this week because of mild temperatures in the main heating regions of the country, the U.S. National Weather Service said on Monday. "Concern about Iran resuming nuclear processing seems to be the only driver," said Kyle Cooper, analyst at Citigroup in Houston. "U.S. weather remains bearish for the next two weeks." U.S. crude had risen to a three-month high of $64.61 early in the session, boosted by a wave of fund-buying that had pushed prices more than $6 higher since late December. Middle Eastern tension has also supported prices. Israeli Prime Minister Ariel Sharon last week suffered a massive stroke and medical consensus is that he will be unable to return to politics, creating a void in the Middle East peace process. European and U.S. officials said that if Iran went ahead with the research, diplomatic efforts to resolve the row would be endangered and Tehran could be referred to the U.N. Security Council for possible sanctions. But for now supplies appear to be ample. The Organization of the Petroleum Exporting Countries meets at the end of the month to reconsider output policy. Ministers have so far indicated there is no need to cut output in the second quarter because prices are stable and demand is strong. PIN/REUTERS