Rio Palace Hotel. Opening panel, from left to right: ?; ?;  Carlos Andrés Pérez (Venezuela), Léopold Senghor (Senegal), Guillermo Ungo (El Salvador), Mário Soares (Portugal), Leonel Brizola (Governor of the State of Rio de Janeiro),  Willy Brandt (West Germany), Pentti Väänänen (Finland), Robin Sears (Canada), Assistant Secretary General of the IS; ?; ?; Lionel Jospin (France); ?. The Congress brought together 77 participants from 50 countries, under the chairmanship of former West German Chancellor Willy Brandt.