With the aims of protecting the Eurosystem from incurring losses in its monetary policy operations, ensuring the equal treatment of counterparties and enhancing operational efficiency, underlying assets have to fulfil certain criteria in order to be eligible for Eurosystem monetary policy operations. ###>L'harmonisation des critères d'éligibilité dans l'ensemble de la zone euro contribuerait incontestablement à assurer l'égalité de traitement et l'efficacité opérationnelle.