Perovskite-type oxide of LaTi0.5Mg0.5O3 composition was synthesized from constituent oxide precursors by mechanochemical activation method in a high power planetary ball-mill, followed by thermal treatment of the product in air. The phase composition after mechanochemical activation of the binary and ternary mixtures was studied by XRPD, while the surface state of the constituent elements was characterized by XPS. The phase composition and surface properties of binary and ternary mixtures obtained by mechanochemical treatment show an affinity of the constituent oxides for the formation of perovskite-type compounds. Using thermally stable phase LaTi0.5Mg0.5O3 (perovskite-type) obtained by the applied procedure, a total oxidation of metane at 750 - 800 degreesC was achieved.