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Oxide-coated metal (Co, Cr and Ti) cluster assemblies whose mean cluster sizes are 8–13 nm have been fabricated by a plasma-gas-condensation type cluster beam deposition technique. With increasing oxygen gas flow rate RO2, the oxide-coated metal cluster-assembled films exhibit a metal–nonmetal transition. In the metallic regime, the resistivity reveals ln T dependence at low temperature due to weak localization of conduction electrons and/or electron–electron interactions in the disordered oxide-coated cluster-assembled films. The ln T dependence still remains for the very thick oxide-coated metal-cluster-assembled films (the actual thickness tc = 2400 nm) which is clearly a three-dimensional system. This behavior can be interpreted by a low dimensionality of the three-dimensional oxide-coated cluster assemblies because of a porous cluster stacking and imperfect or non-uniform oxide shell. [ABSTRACT FROM AUTHOR]