Article L5421-1 of the French General Code of Local Authorities
Interdepartmental institutions or bodies are freely constituted by two or more departmental councils of even non-adjacent departments; they may also associate regional councils or municipal councils. Interdepartmental institutions or bodies are public establishments, invested with legal personality and financial autonomy. They are administered in accordance with the rules laid down for departmental management. Their administration is carried out by departmental councillors elected for this purpose. Where they involve regional councils…