Protocol of Ouro Preto

The 1994 Protocol of Ouro Preto was the continuation of economic policies setting up a customs union, as set forth four years earlier in the Treaty of Asunción by the four original Mercosur states, Argentina, Brazil, Paraguay and Uruguay.^[1] It officially established Mercosur as an international customs union.

Protocol of Ouro Preto

Additional Protocol to the Treaty of Asunción on the Institutional Structure of MERCOSUR
Signed	December 17, 1994 (1994-12-17)
Location	Ouro Preto
Effective	December 15, 1995 (1995-12-15)
Amendment	Treaty of Asunción
Signatories	Argentina Brazil Paraguay Uruguay
Languages	Spanish Portuguese