Volkswagen AG, BMW AG, Daimler AG and Robert Bosch GmbH were among six companies raided by Germany’s antitrust regulator in June in a probe of steel purchasing by the auto industry. There are indications that antitrust rules may have been violated, and the raids were conducted to investigate the facts, Kay Weidner, spokesman for the Federal Cartel Office, said in an e-mailed statement on Tuesday. He declined to identify any company. BMW, VW, Daimler, Bosch and ZF Friedrichshafen AG confirmed that they were raided and said they are supporting the investigations. Carmakers are one the major pillars of the German economy, and steel is a key component for auto companies. On average, about 900 kilograms (1,984 pounds) of steel is used in every car, according to the World Steel Association.