This article deals with the privatization of telecommunications in the three largest Latin American countries, Argentina, Brazil and Mexico. Labor unions have strongly affected the way telecommunications have been privatized in Latin America and its timing, but they have not been able to keep their traditional influence from waning. Comparing Argentina and Mexico brings to light opposite models of labor relations based, for the one, on the denationalization of management and loss of guaranteed jobs for wage-earners and, for the other, on the maintenance of control over telecommunications by local entrepreneurs and the preservation of guaranteed employment. The more recent privatization implemented in Brazil has fueled debate about the consequences on collective action in an era of open-market telecommunications. - Special issue: Latin America. (C) 2004 Elsevier SAS. Tous droits reserves.