CCIES es miembro de la asociación europea E3PO.

E3PO is a non-profit association located in Brussels representing the Voice of European PPP Operating Companies in Infrastructures and Services that was created in 2008.

E3PO consists of national, European and international federations, representing sectoral and pluri-sectoral private companies that are active in the operation of Services of General Economic Interest (SGEI) under contract concluded with public authorities following a competitive bid in the following sectors: motorways, water and sanitation, waste management, energy efficiency, public transport, catering.