Oil companies are blocking the access of renewable fuels to the U.S. market by using anti-competitive practices, two U.S. senators claim in a letter to the U.S. Federal Trade Commission.

Senators Charles E. Grassley, R-Iowa, and Amy Klobuchar, D-Minn., said that ever since renewable sources of energy have increasingly been explored, the U.S. oil industry has publicly stated its intention to retain its market dominance. Moreover, oil companies are purposefully working toward undermining attempts of renewable energy companies to distribute fuels that could help to meet the Renewable Fuel Standard, the letter added.

A copy of the letter has also been sent to the U.S. Attorney General Eric H. Holder Jr., since the two lawmakers explained they had heard allegations that oil companies require retailers to sell premium gasoline, "blocking the use of the current retail infrastructure to sell renewable fuel."

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In response to the letter, U.S. Federal Trade Commission chairwoman Edith Ramirez stated that the commission will investigate the allegations and will look into concerns over possible anti-competitive practices. She also said that the agency will do its best to "identify, prevent and prosecute practices in petroleum and other markets that violate any statute or rule that the agency enforces."

Reid Porter, a spokesman for the American Petroleum Institute, commented that the allegations were an attempt to distract public attention from the fact that the Renewable Fuel Standard was not working.