This study aims to analyse the importance of the disclosure of ANEEL's social and environmental report to the Level of Disclosure of Environmental Information of Brazilian companies in the electricity sector in the period from 2006 to 2009. The analysis was focused on 60 companies dedicated to various activities in the value chain of the electricity industry. The metric totals 90 indicators, including 34 from the global reporting initiative (GRI) and 56 from the National Agency of Electrical Energy. In this research content analysis and correspondence analysis in panel were the used techniques, respectively. As data collection and analysis technique, the research used content analysis and correspondence analysis in panel techniques, respectively. Results showed a significant evolution in the disclosure level of the entities under study, as a result of ANEEL's social and environmental report disclosure. Despite the growth in the voluntary disclosure of the GRI model, it does not reach the level of disclosure resulting from the Brazilian regulatory agency's guideline.
Keywords: environmental indicators, environmental disclosure, electricity industry, GRI, global reporting initiative, ANEEL report, Brazil, value chain, regulatory agency guidelines