The privileged ties that unite Marseille with its twinned cities, the cooperation agreements and the Alliance charters signed with cities from around the world attest to Marseille's openness to the international arena . Furthermore, Marseille is a member of several city networks:

• Medcités, network of coastal cities in the Mediterranean Region (protection and management of the environment)

• Eurocités, network of major non-capital metropolises in Europe

• AIVP, International Association of Cities and Ports

• Barcelona-Gênes-Lyon-Marseille Alliance Charter (town management, international relations, cooperation)

• AF.CCRE, French Association of the Council of Communes and Regions of Europe , the largest European network of local authorities, which aims to promote dialogue between the commission and regional authorities.

• UCLG (United Cities and Local Governments) : global organisation of local authorities (unification of the WFUC (World Federation of United Cities) and the IULA (International Union of Local Authorities).