| Contracting Parties/Signatories | Signature | Instrument | In Force | Details |
|---|---|---|---|---|
| Bolivia (Plurinational State of) | May 28, 1996 | Ratification : July 14, 1998 | August 25, 1999 | |
| Colombia | May 28, 1996 | Ratification : July 21, 1999 | August 25, 1999 | |
| Ecuador | May 28, 1996 | Ratification : June 12, 1997 | August 25, 1999 | |
| Peru | May 28, 1996 | Ratification : September 12, 1997 | August 25, 1999 |