WASHINGTON — The Environmental Protection Agency is expected to raise the maximum amount of ethanol that can be blended with gasoline for vehicles manufactured since 2007.

According to people with knowledge of the announcement, the EPA could say as soon as today the newer vehicles are able to handle 15 percent ethanol, up from the current maximum of 10 percent for the corn-based fuel. The sources spoke on condition of anonymity because they were not authorized to discuss the decision.

The ethanol industry has maintained there is sufficient evidence to show a 15 percent ethanol blend in motor fuel will not harm engine performance. But the auto industry, environmentalists and a broad coalition of other groups have argued against an increase and called for more testing.

Opponents argue the increase in production of corn and its diversion into ethanol is making animal feed more expensive, raising prices at the grocery store and tearing up the land.