The European Commission has extended the in-depth investigation it began in 2007 under EC Treaty State aid rules into the regulated electricity tariffs enjoyed by certain large and medium-sized companies in France. This system, intended as a transitional measure, has so far benefited a small group of companies that essentially comprise the country’s largest electricity users, giving them an economic advantage and distorting competition in the EU Single Market. The investigation is being widened to look at the prolongation of the system of “return tariffs” (or “TARTAM”) until June 2010 and its extension to new beneficiaries. The extended investigation does not cover the regulated tariffs applicable to households and small businesses.