International Law Commission, Geneva, 1969. Former Member, Congress, Minister of State and Ambassador. Professor, Private International Law, (conflicts of law) Universidad Mayor de San Andrés and Universidad Andina Simón Bolivar. Chairman, Andean Group's Paramount Body. President, Interamerican Social and Economic Council. Chairman of the Board, Andean Development Corporation. Chairman, Organization of American States Permanent Council. Negotiator, Treaty of Montevideo (Montevideo based Latin American Integration Association, ALADI). Bolivian Representative and Chairman, Interamerican Specialized Conference, Private International Law, 1983. Currently Member of the Permanent Court of Arbitration (The Hague).