Investigating the Effects of Ownership Structure on The Performance of the Companies Accepted in the Tehran Stock Exchange

This study is an attempt to investigate the effects of ownership structure on the performance of the accepted companies in the Tehran Stock Exchange. For testing the hypotheses, the statistical "panel data" technique was employed. For testing each hypotheses, four models based on different independent variables were introduced. The statistical population included 66 companies in the period between 2003-2008. Based on the research results, all the hypotheses except the fourth one, were confirmed. The findings reveal a significant negative relationship between the "institutional ownership" and companies’ performance; and the relationship between the "corporate ownership" and companies’ performance is significantly positive. "Management ownership" would affect the performance significantly and negatively. For "foreign ownership", there is no information that would indicate the ownership of foreign investors in our samples companies. In "private ownership", it is better for corporate investors to handle the principal ownership. In general, there is a significant relationship between companies’ ownership structure and their performance.