Examined are metal-filled polymer compositions on the base of low density polyethylene (LDPE) with a differing content of magnesium (10, 20, 30 and 40%). After irradiation with gamma rays (60Co) of a well-defined dose a transition from high to low resistivity is observed for the 30 and 40% Mg composites. The radiation-induced change of specific volume resistivity permits the development of conducting polymer materials on the base of metal-filled composites with a wide range of application in engineering.