The oil industry is joining with food manufacturers, livestock producers and fast-food restaurants in an effort to block an increase in the amount of ethanol that can be added to gasoline.

They say the Environmental Protection Agency doesn't have the authority to permit higher ethanol blends in some vehicles but not in others. The EPA last month agreed to allow cars and trucks that are 2007 and newer to run on gasoline with 15 percent ethanol, a blend known as E15.

The ethanol limit has long been 10 percent for all vehicles with the exception of "flexible fuel" cars and trucks that are manufactured to run on ethanol or gasoline.

"This legal action will give EPA a second chance to get this important decision right," said Scott Faber, vice president for federal affairs at the Grocery Manufacturers Association.

His group was joined by the American Petroleum Institute and a series of livestock and food industry groups, including the National Pork Producers, National Council of Chain Restaurants and the American Meat Institute, in asking a federal appeals court to block the EPA's E15 decision.

Gasoline refiners also may challenge the decision, as well as engine manufacturers and other sectors that have expressed concerns that misuse of E15 would damage motors.

A proposed warning label on E15 gasoline pumps isn't enough to prevent consumers from putting the fuel in cars and equipment for which it is not approved, said Kris Kiser, a spokesman for the Outdoor Power Equipment Institute, whose members make lawn mowers, leaf blowers, garden tractors and other products.

Livestock producers and food groups have long argued that ethanol usage is driving up the cost of producing meat, milk and other products by keeping prices for commodities higher than they otherwise would be.

Their concerns were underscored by Agriculture Department reports Tuesday that sent corn and soybean prices higher on projections of tight crop supplies, growing ethanol production and increased export demand.

"This challenge to the EPA's decision is necessary to reduce the strain that ethanol production from corn has placed on U.S. agriculture," said Scott Vinson, vice president of the National Council of Chain Restaurants.

Some in the ethanol industry are unhappy with the EPA, too, both because it limited E15 to the newest vehicles and because of the orange warning label that the EPA has proposed for service-station pumps. The agency is waiting on research to be completed before expanding approval to include vehicles made since 2001.

Tom Buis, CEO of the ethanol trade group Growth Energy, said opponents of his industry were trying legal means to slow the growth of biofuel production because they have been "unable to dispute the overwhelming science in favor of E15."

The EPA said its E15 decision was "based on strict adherence to the Clean Air Act and grounded firmly in science. The agency relied on numerous rounds of rigorous testing on 19 car models and, at every step, worked in close consultation with automakers and fuel suppliers."