In this part of the present work, the catalytic properties in methane oxidation of perovskite-type mixed-oxides, LaCo1-xFexO3 prepared by reactive grinding of the component oxides were studied. A fine control of the nature and concentration of the various sites active in oxido-reduction catalysis was performed by applying the comprehensive picture of the effects of thermal pretreatment of the mixed-oxides generated by this technique, developed in part I of this contribution. These properties which were previously illustrated by the kinetics of complete oxidation of n-hexane over five nanocrystalline LaCo1-xFexO3 catalysts treated in parts II and III are now demonstrated by a kinetic study of methane oxidation over the same catalysts. (C) 2002 Elsevier Science B.V. All rights reserved.