Castel, Jean-Gabriel Keywords: Cartels and monopolies | Extraterritorial jurisdiction | Mots clefs: Cartels et monopoles | Extraterritorialité des lois | ABSTRACT Jean-Gabriel Castel studies in his course the extraterritorial effects of competition rules. He devotes the initial developments of his study to an analysis of the power of the State to apply and interpret its law in a way that confers extraterritorial effects on it. The author then examines the practice of certain States with regard to the extraterritoria…