House and Senate negotiators on the US energy bill will be asked to give ethanol a larger share of the US fuel market sooner than is now proposed, backers of the renewable fuel said, according to Reuters. Reuters said both House and Senate support a so- called renewable fuels standard that would require use of five billion gallons a year of ethanol at the end of a decade - the Senate puts the target at 2012, the House sets it at 2015. The news agency said US use of ethanol has boomed in the past few years, as a rival fuel additive, methyl tertiary butyl ether, has fallen into disfavor as a ground-water pollutant. Both products are used to create cleaner-burning fuels, the report noted. A spokesman told the news agency the Renewable Fuels Association regarded the proposed Senate mandate of five billion gallons in 2012 as "one of the cornerstone things." RFA would prefer a starting guarantee "closer to 3 billion" gallons in 2005, the report added. Ethanol output may total 2.7 billion gallons this year, Reuters said, adding that, under the House bill, the earmark for renewable fuels would begin at 2.7 billion gallons in 2005 while the Senate begins at 2.6 billion gallons in 2006. Both chambers would eliminate a requirement now in place for use of oxygenated fuels, Reuters said. Reuters said there are 73 ethanol plants in 20 states, spanning the nation but mainly in the Midwest, while 13 additional plants are under construction.