The European Community Regulation No. 1606/2002 required all European Union listed companies to prepare their consolidated financial statements in accordance to IFRS as from 1 January 2005 (Pagletti, 2009). The main purpose of the introduction of IFRS in EU is the comparability and the quality improvement of the firms’ financial statements. In the framework of the improvement of the amount and the quality of the information provided to investors, lenders etc the importance of the narrative portion of the financial statements has been recognized by practitioners and researchers. Our study investigates the relationship between ESG (environmental, social and governance) ratings of firms and its stock returns, risk-adjusted return and volatility divided at three important periods. The period prior the implementation of IFRS (2002-2004) after the adoption of IFRS (2005-2007) and the period to the post 2008 financial crisis era. Furthermore, using the multicriteria method of PROMETHEE II to measure the level of disclosure of accounting information in 524 stock market listed companies. Acknowledgments «This project is implemented through the Operational Program "Education and Lifelong Learning", Action Archimedes III and is co-financed by the European Union (European Social Fund) and Greek national funds (National Strategic Reference Framework 2007 - 2013).
Keywords: PROMETHEE II, non-financial Information, ESG, business reporting, disclosure quality.