SUMMARY
This study characterizes the Mergers and Acquisitions (M&As) processes that achieved better performances in internal value and synergy generation. The M&A theme is not particularly new in the strategy literature, which does not mean that it is consolidated, at least not from the point of view of these strategies results. Academic literature on the topic stablishes that the search for synergies is the key reason for these strategies, although the measurement of these synergies is not a simple task. This study evaluated 154 M&As processes using three variables related to market value creation and operational efficiencies creation. The M&A processes were classified according to the type of agglomerative process, economic sector, nationality and positioning of companies in the production chain. Statistic data were analyzed with descriptive statistics, variance analysis and cluster analysis. The results indicate that most of the cases resulted in mild negative or positive results, with no significant differences between the results of processes carried out in different sectors of the economy. The cases that achieved better results were those in which companies already had previous experience in M&A and held knowledge of the acquired enterprise, which reiterates the need for prior planning and analysis to the generation of the expected synergies and value creation.