Résumé : This article puts forward the hypothesis that the sector-­based structuring of policy agendas, debates and decision-making can impede policy change when dealing with issues with an inter-sectoral scope. In so doing, it takes the politics of services of general interest regulation in the European Union as a case study for theory building. Drawing on historical and discursive institutionalism, it empirically demonstrates how feed-back effects of historically entrenched policy arrangements, on the one hand, and discursive interactions among agents, on the other, considerably constrain and shape the formation of preferences and coalitions. Since the sectorization of policy making is a salient feature of contemporary governance, this hypothesis is relevant for understanding policy change in connection with a broad range of policy issues and polities.