The economic and social phenomena which play a role in shaping cities are largely unaffected by institutional boundaries. In other words, public actors in "cities unbound" deal with problems that are not restricted to their own institutional area, and that cannot be solved at that level either. In this article, we have focused on the way public actors come to an agreement on the rules (norms, ratios, perimeters, etc.) that serve as guidelines for local public action. What are the different rationales that govern this "rule-building process" and how do the actors reach agreement when they have diverging points of view? In our investigation, we gave priority to the ideological and area-based aspects by examining how the negotiations between local authorities and the state and the actions that are undertaken reflect the ideologies of local actors and the interests of the areas and the people they represent. In the context of French debate on the reform of local institutions, two types of local actors more specifically aroused our interest: the intermunicipal authority and the "Département". In recent years, the development of intermunicipal institutions received a real impetus from the 1999 local government act. In order to meet the changing needs of urban areas, the act created a new kind of intermunicipal authority, the "Communauté d'Agglomération", which was invested with extensive responsibilities in the areas of local development and planning. As no elections are held to appoint individuals to intermunicipal authorities, these institutions are not politically independent of the governments of the municipalities that comprise them. Do the intermunicipal authorities take part in defining new local issues? How do they contribute to the coordination of policies for different sectors at their own level? Based on a case study of the "Communauté d'agglomération du Val-de-Bièvre" in the Greater Paris Region, we will highlight the role of intermunicipal authority in public rule-building process. On the other hand, the continued existence of the Départements - subregional institutions that were created during the revolutionary period and that became local authorities in 1871 - is frequently questioned. Though they have traditionally focused on public action in rural areas, the Départements have recently been given extended responsibilities for transport and housing policy. We will show that, in contrast with what is usually assumed, the Départements do take part in urban policies, either through their own competencies or by making financial contributions to assist the actions of other institutions. We shall demonstrate this by referring to the actions of the "Département du Val-de-Marne", which is situated in the inner ring of the Paris suburbs, in relation to two development projects which were implemented at the level of the "Communauté d'agglomération du Val-de-Bièvre".