The purpose of this paper is the conceptualisation of the notion of enterprises’ structural power. It allows to draw the attention to the process of diversification of enterprises and building of complex and multidimensional ownership structures as possible sources of the increase in the companies’ power and the possibility of its use and abuse in order to limit the competition and perform better on the market. The concept of structural power is a part of the scientific discussion on the sources and possibilities of using enterprises’ market power, and fits into the current research on one of the fundamental problems of economic theory: how to protect competition internationally and, therefore, determine the limit when the natural and desirable behaviour of enterprises aimed at increasing their international competitiveness begins to distort competition and adversely affect economic development. The analysis shows that the potential influence on other market participants may arise not only from the firm’s position on the relevant market and other factors related to its specificity, but also from the various types of linkages between firms.