In the utilities sector, the OECD regulatory restrictiveness index provides a measure of liberalisation in different sectors and countries. However, the index does not provide information about the political and administrative arrangements that manage regulation. The way regulation is organised between a wide set of authorities with general or sector-based competencies situated at multiple levels is as much a critical success factor as the abolishment of anti-competitive regulations to reach the objectives of the European liberalisation programs. The aim of this paper is to present a typology of regulatory arrangements based on two indices, namely the procedural coordination index and the centralisation index. The typology is built on the assumption that an effective market depends on the degree of coordination between all the public (and private) actors involved in regulation, i.e. the extent to which all the regulatory tasks within the arrangement are included, and, the extent to which the tasks of the respective actors are mutually aligned. It measures the proliferation of regulatory authorities, the degree of specialisation of the tasks assumed by each authority and the coordination between them, as well as the centrality of the main regulators within the arrangement. A first test of reliability of this typology of regulatory arrangements is made on the cases of the energy and telecommunications sectors in Belgium. The paper ends with discussing the strengths and weaknesses of the indices, as well as the relevance of the indices for descriptive and explanatory research on the organization of regulatory tasks.