It is a complex task to determine the potential effects of a merger on the degree of competition on a market. The decision to defend fair competition by approving or rejecting a merger is, therefore, difficult, and it creates uncertainty in the companies evaluating a merger. Establishing an explicit policy for the evaluation of mergers, consisting of an analytical framework to determine how likely it is that a merger will reduce the degree of competition on a market, would meet two objectives: it would systematize the analysis and allow private players to anticipate the actions of regulators, which would, in turn, reduce the uncertainty. This article proposes a merger policy for Chile that fulfills the above objectives, in line with the policies applied in developed countries.