Brussels (dpa) - The European Commission launched a formal investigation Monday into three ethanol companies suspected of illegally colluding to increase prices, which would drive up the cost of renewable energy.The three companies - Abengoa of Spain, Alcogroup of Belgium and Swedish firm Lantmannen - produce, distribute and sell ethanol, an alcohol made from crops such as wheat, maize or sugar beet that is mainly added to gasoline or used as a biofuel.The European Union‘s executive suspects the three companies of manipulating ethanol benchmarks published by the price reporting agency Platts, by colluding over their bids in order to drive up prices.This could lead to a reduction in the use of biofuels as an alternative to fossil fuels, harming consumers and the environment, the commission said."Competitive biofuels markets are crucial to promote cleaner transport and to cut greenhouse gas emissions," EU Competition Commissioner Margrethe Vestager said in a statement.Investigations began in 2013, when the commission carried out a first round of unannounced inspections, followed by more in the subsequent years.The EU‘s competition watchdog can fine companies engaging in illegal anti-competitive behaviour up to 10 per cent of their turnover.It is also conducting a separate probe into whether producers or traders of bioethanol for use in fuels, drinks, medical products, chemicals or cosmetics have illegally fixed prices or shared markets and customers.