Think tanks have experienced a significant development in France for 20 years. Some promote neoliberal ideas such as the Institut Montaigne, whereas some others are more progressive as Terra Nova. We aim at analyzing the involvement of business leaders in the boards of these organizations, in order to highlight their political mobilization. From the composition of the 70 main think tank boards in 2008, we investigate the network structure of board co-memberships. Then we focus on the position of business leaders in this network. Finally, we look at the role of executive and non-executive directors of the 100 main companies in France. Despite their heterogeneity, most think tanks are rather well integrated thanks to their common board members. And business leaders play a major role in this cohesion. They stand at more central positions than the other categories of members (political leaders, scholars, journalists, bureaucrats…). Furthermore the interlinkages among them are more cohesive and centralized. These results illustrate the relational proximity of the business elite with the political and intellectual elites in particular. But they also reflect a better capacity from business leaders to defend their own ideas and values through these organizations, generally talking in the name of a so-called general interest.