Résumé en anglais

This paper aims to examine the effect of many ownership features on firm's disclosure quality using the theoretical framework of the agency theory, which states that investors information demand increases with agency costs of the firm. Public ownership increases agency costs and therefore should improve shareholders' information need and enhance disclosure. After controlling for size, debt and multi-quotation, our tests indicate significant negative associations between disclosure quality and ownership concentration, family control and separation between voting and cash flow rights. The results also show that French listed firms providing good disclosure are more likely to offer stock option plans for their executives, are listed on American stock exchange and are included in CAC40 index