The mismatch between the supply size of high-order services and the size of municipalities, often called spillovers, gives rise to a need for municipalities to co-operate. In Switzerland, canton laws on municipal organisation provide the directives concerning co-operation among local public entities. Inter-municipal collaboration can take on different forms: co-operation based on private law, inter-municipal conventions, associations of municipalities, and in the extreme case of complete integration, the merger. All of these forms of partnerships have advantages, but can also cause disadvantages and difficulties when applied. One possible alternative is to adopt the mode of a Holding Company for Public Shareholdings (HCP), which should favour the public-private partnership.