The relationship is derived, within the scope of irreversible thermodynamics, to predict the dc conductivity of a disperse system of the "conductor-in-conductor" type, The results enable one to describe the dc conductivity of the system with the help of the preliminary known expression for the ac conductivity as a function of the specific conductivities of the constituent phases, The derived relationship is used to study the systems with various types of morphology, It is discussed how the difference between the ac and dc conductivities depends on the system morphology and transport characteristics of both the connected and the disconnected constituent phases, Some ways of using the results are suggested.