Purpose - The purpose of this paper is to add to our understanding of the monitoring role of multiple large shareholders by examining their impact on the informativeness of firms' earnings. Design/methodology/approach - We use regression models that relate earnings to stock returns for a sample of 402 French publicly traded firms covered during 2003-2007. Findings - We show that earnings informativeness is significantly positively related to the owner's ultimate cash flow rights. Consistent with the alignment effect, stock ownership aligns management and shareholders interests which reduces managers' incentives to manipulate accounting information. We also find that earnings informativeness is significantly negatively related to the excess control of the ultimate controlling shareholder. This result supports the entrenchment effect and suggests that controlling shareholders have greater incentives to obscure accounting figures when expropriation is likely. Finally, control contestability of the largest controlling shareholder mitigates information asymmetry problems thereby enhancing earnings informativeness. Limitations/implications - Our findings stress the importance of MLS in enhancing internal monitoring and mitigating agency costs. Because France is characterized by a weak legal system, highly concentrated ownership structures and excess control, our results provide valuable insights to mitigate extreme agency problems. Originality/value - The paper adds to the literature on corporate governance and the quality of accounting information by investigating strategic interactions between various blockholders and their impact on earnings informativeness. The study complements prior studies on the monitoring role of MLS by demonstrating that both their presence and control size translate into significantly greater earnings informativeness.