Article XVIII

This Convention shall not abrogate multilateral or bilateral copyright conventions or arrangements that are or may be in effect exclusively between two or more American Republics. In the event of any difference either between the provisions of such existing conventions or arrangements and the provisions of this Convention, or between the provisions of this Convention and those of any new convention or arrangement which may be formulated between two or more American Republics after this Convention comes into force, the convention or arrangement most recently formulated shall prevail between the parties thereto. Rights in works acquired in any Contracting State under existing conventions or arrangements before the date this Convention comes into force in such State shall not be affected.