The purpose of the study is to find the optimal ratio of the equity and debt capital for one of the enterprises of the Russian coal industry using proposed optimization model of the capital structure. In the recent years Russian coal companies endured external and internal challenges connected with access restrictions to the international capital markets due to sanctions and tightening environmental regulations, as well as all time relevant problems of increasing returns and economic benefits from equity capital. The result of the research was the developed economic and mathematical model of the capital structure specific for the mining industry with the system of restrictions ensuring an acceptable level of risk. The model belongs to the optimization class and allows, using the predicted values of the indicators of the financial statements of the enterprise, to obtain the optimal capital structure for the forecasted period. The model is solved using mathematical method for finding a Pareto-optimal solution. As a result of the application of the proposed model to the indicators one of the largest Russian coal company Siberian Anthracite the recommended ratio of the equity and debt capital was revealed. The received numerical result differed from the actual capital structure of the company due to the additional loans during last years. Application of the model can increase the quality of the decision-making process and increase the economic and financial efficiency of the companies performance.
