| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| FRANCE | Signature | 03/04/1958 | |
| GREECE | Signature | 01/08/1958 | |
| GREECE | Undertaking | 23/04/1959 | |
| ITALY | Signature | 30/07/1958 | |
| ITALY | Communication | 22/05/1959 | |
| PORTUGAL | Signature | 08/04/1958 | |
| SPAIN | Signature | 09/04/1958 | |
| TUNISIA | Signature | 03/04/1958 | |
| TUNISIA | Undertaking | 12/05/1959 | |
| UNITED KINGDOM | Signature | 31/07/1958 | |
| UNITED KINGDOM | Ratification | 19/06/1959 |