The paper deals with the topic of concentration in the retail trade. At the very beginning of the paper the term of concentration is defined. Furthermore, process of taking over the company is explained in detail, as a part which is of great importance to this paper. Then the models of concentration are displayed, causes and motives, and advantages and disadvantages. Legal framework of concentration is explained in detail and also the role of the Agency for Protection of Competition. After that, seeks to show the development of retail on the Croatian market from the nineties, until the beginning of concentration, and of the situation in times of recession. In the research part of the paper seeks to better systematize and display sequence of takeover which was affected by a number of factors. Takeover was specific and the largest in the region, and as such very interesting to analyze. As results of the study, the degree of integration is considered and the realization of synergy effects. At the end is the conclusion in which has been used publicly presented assess from the CEO of Konzum on the results of the acquisition and plans for the time to come. The entire research produced the conclusion that the takeover has been justified because it has shown synergy effects and a positive result in the first year. Then in the list of literature states used literature and sources such as books, scientific and professional articles and Internet resources. It also contains a list of all the paper presented tables and figures and briefly something about the author of the paper in the form of CV.