The paper analyses possible directions for sustainable development of heat supply systems of the countries participating in the Eurasian Economic Union when creating a united electricity market. The present problem is subject to the fact that the key technology for the energy products production which forms the basis of the energy systems of the former Soviet Union countries is combined generation of electric and heat energy at the CHP. At the same time, this type of combined production is ineffective in the energy market conditions, and creation of a unified energy market can significantly affect the energy and economic efficiency of regional heat supply systems and energy security of states. In this regard, possible ways of sustainable development of regional heat supply systems in the context of integration of market pricing mechanisms are proposed and risks of various business models of commercial activity in the sphere of heat supply are identified.