Open market share repurchases are strictly regulated to prevent companies from profiting from insider information. We examine compliance with these rules in France, where the mandatory disclosure of share repurchases provides detailed information on repurchases actually undertaken. Using a database containing 36,848 repurchases made by 352 French firms over the period 2000-2002, we show that very few firms fully comply with the regulations for all their buybacks. Non-compliance has an adverse effect on liquidity only for the smallest and least liquid firms.a Both authors are from DRM-Cereg, University Paris-Dauphine, place du Maréchal de Lattre, 75775 -Paris cedex 16 -edith.ginglinger@dauphine.fr (corresponding author), jacques.hamon@dauphine.fr. We are grateful to Gérard Rameix for providing the data about daily repurchases. We would also like to thank Myron Slovin and Marie Sushka for their comments.2