(Reuters) - A coalition of ethanol and farm groups sued the U.S. Environmental Protection Agency on Tuesday, challenging its decision to free three refineries, including one owned by billionaire investor Carl Icahn, from annual biofuels requirements.

The groups, including the Renewable Fuels Association and the National Corn Growers Association, filed the challenge in a U.S. Court of Appeals for the 10th Circuit in Denver, according to a statement from the coalition. The lawsuit targets three waivers doled out to refineries owned by CVR Energy Inc, in which Icahn hold a majority stake, and HollyFrontier Corp.

By Chris Prentice & Jarrett Renshaw.