. At a domestic level, cooperative joint ventures, outsourcing, and specialization have been the predominant forces of concentration. At the international level, fewer correspondent banks and the emergence of new cross-border infrastructures have been key factors. At the domestic level, cooperation approaches in the G10 countries have a long tradition, particularly in the savings, cooperative, and community banking sectors. Small and medium-sized savings and cooperative banks often outsource payment activities or securities-related back-office activities to sector-specific cooperative interbank clearing mechanisms. In Germany, for example, the savings and cooperative banking sectors have established their networks based on internally agreed exchange and settlement procedures.