The article presents the value of the vertical integration for the development of enterprises in the metallurgical industry. We consider the nature and forms of integration. Horizontal integration promotes unification of enterprises in one branch, which are characterized by the technological community and homogeneity of products. Vertical integration involves the association of companies operating in the same or different branches connected together by a single value chain. The authors have proposed and tested the mechanism of interaction between participants of the integrated structure using a model of transfer pricing of A.S. Pleshchinsky as a methodological basis for assessing the economic effect and a tool for harmonizing the economic interest of the participants of vertical integration. The testing results confirmed the hypothesis of an additional effect resulted from economic cooperation between the participants of integrated structure based on transfer pricing, which allows increasing production volumes by reducing the cost of purchasing raw materials at intermediate stages of the process and thereby increasing the growth of economic indicators.