During the last years the cooperation among national bank supervisory authorities and the harmonisation of bank supervisory rules has been spectacular.

This resulted in the creation, on the one hand, of an international regime for the prudential regulation of international banks under the auspices of the Basle Committee on Banking Supervision and, on the other hand, of a regional, supranational regulatory regime within the single market of the European Union.

In both cases the minimal harmonisation of capital adequacy regulations was chosen as the most adequate means for preserving the stability of the international banking system against excessive bank exposure to financial risks.

The present study is analysing the foundations and the content of these two regulatory regimes, by inquiring their similarities and differences, the links connecting them, and the way in which their rules influence the national legislation of participating member states.