Résumé en anglais

We examine how ownership concentration and the separation of ownership and control affect market liquidity in France. We find that firms with a large insider blockholder exhibit significantly lower liquidity. Different methods of concentrating control affect liquidity in different ways. Pyramid structures negatively affect liquidity for all pyramiding firms. Double voting right shares, a French specific means of control enhancement rewarding long-term shareholders, lead to increased liquidity for outside investors of small, family- firms, by reducing the probability of informed trading.