The approaches regarding the hierarchy in the application of sector-specific regulation and competition law in the European Union and the United States differ strongly. In the European Union the Deutsche Telekom case confirmed that competition rules will continue to apply despite the existence of sector-specific regulation, unless the system of sector-specific regulation confers upon the dominant firm no margin of freedom in which to pursue an independent pricing policy. In the United States the Supreme Court judgment in Trinko concluded that there is no room for antitrust remedies when sector-specific regulation is in place. However, the recent Supreme Court judgment in Actavis might indicate a change of this policy in the United States. This article analyses and compares the legal situation in the European Union and the United States regarding the relationship between regulated networks and competition law. This is followed by a direct comparison with regard to criteria necessary for a successful legal policy. The aim is to stimulate a discussion as to whether one approach is preferable to the other and/or whether a global approach on the antitrust treatment of regulated network industries, taking account of the different legal systems, should be developed.