WASHINGTON - Minnesota has four companies that could be among the first in the country to sell a richer blend of ethanol and gasoline.

The Environmental Protection Agency on Monday announced its approval of 24 companies to offer a blend that is 15 percent ethanol and 85 percent gasoline. Among the first companies lining up to produce what is commonly called E15 are the owners of ethanol plants in Benson, Marshall and Fairmont and Wayzata-based Cargill, Inc.

Advocates say the mixture of gasoline and renewable ethanol could sell for 5 to 10 cents per gallon less than regular gasoline at a time when soaring gas prices dig deeper than ever into Americans' pocketbooks.

"There should be some E15 in the market in the next month or two," predicted Tom Buis, CEO of Growth Energy, a trade association for ethanol producers. "Market economics should drive it."

Cargill did not hazard a guess of when E15 might actually be available to motorists.

"This is an important and positive step toward increased usage of ethanol," company spokesman Pete Stoddart said. "But more steps are needed for E15 to gain widespread adoption in the market."

Among the biggest hurdles is that EPA restricts E15 to vehicles built in 2001 and later. The restriction requires companies to file plans to ensure E15 is kept out of older vehicles, as well as boats and gasoline-powered equipment, where the EPA says it may cause damage.

Minnesota requires all gas stations in the state to offer 10 percent ethanol (E10), said Christine Connelly of the Minnesota Department of Agriculture. For now, it will not do the same for E15.

"Minnesota law says that unless it's allowed in all vehicles, regardless of year, you can sell it, but it won't be mandated," Connelly explained.

While the lack of a mandate puts a crimp in marketing E15, Buis called Monday's EPA announcement a major move for those who earned the agency's approval for production. "You ask why this is needed?" he said. "For 40 years, we have been addicted to foreign oil."

The American Fuel & Petrochemical Manufacturers Association was not enthusiastic. "EPA's hasty attempts to speed introduction of E15 ... could endanger the safety of American consumers, threatening their vehicles and gasoline-powered equipment with possibly severe damage," association president Charles T. Drevna said. "This action is more about political science than real science because it is designed to protect the ethanol industry rather than the American people."

The EPA said the Department of Energy did extensive testing of E15 in vehicles.

Jim Spencer • 202-408-2752