The Guarantor Authority also sent a request for information to 25 other companies The Antitrust Authority has initiated four investigative proceedings - and as many precautionary sub-proceedings - against the companies Iren, Iberdrola, E.ON and Dolomiti, suppliers of electricity and natural gas on the free market. It also sent a request for information to 25 other companies : A2A Energia, Acea Energia, AGSM ENERGIA, Alleanza Luce & Gas, Alperia, AMGAS, ARGOS, Audax Energia, Ax