| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| BELGIUM | Ratification | 27/08/1957 | |
| FRANCE | Ratification | 27/12/1956 | |
| GERMANY FEDERAL REPUBLIC | Ratification | 28/12/1956 | |
| ITALY | Ratification | 12/06/1958 | |
| LUXEMBOURG | Ratification | 11/03/1957 | |
| NETHERLANDS THE | Ratification | 09/10/1958 | |
| UNITED KINGDOM |