This study aims to analyze institutionalization from the perspective of negotiation processes that foster the economic integration agreement that have served Colombia, South Korea and Mercosur as they integrate economically with other regions, considering bilateral negotiations or bloc negotiations. The present research is based in two main theories: new-institutionalism and constructivism, that serve as foundation to explain the main research question: How does the level of institutionalization impact the strategies of negotiation and design of agreements? Finally, is it better to negotiate bilaterally or as a bloc? Therefore, this paper accounts with two kinds of studiesa qualitative and a quantitative one.