EN
The paper looks at the protection of the existence of competition (antitrust) from the perspective of the traditional division of law into public and private. The basis for the paper is the fact that competition law has, since its birth at the end of the 19th century, hovered between the limits and principles of public and private law. The first part describes current “invasions” of competition law into both the private and public spheres with the objective of achieving greater effectiveness of public law protection of competition. The second part illustrates the difficulties caused by the blurred line between the protection of the general or public and the private interests on the national level in the context of the protection of suppliers of large retail chains and on the level of the European Union in the first attempts to regulate the competition among multisided online platforms. Despite certain critical comments, the paper does not deny the benefit of competition law in maintaining a competitive market economy and achieving social acceptance thereof by preventing the excessive concentration of market power in the hands of some competitors.