Aromatic hydrocarbon compounds are produced by a process of contacting one or more aliphatic hydrocarbons containing from 3 to 6 carbon atoms with a catalytic composition comprising (i) gallium, (ii) at least one lanthanide element, and (iii) a zeolite selected from the group consisting of the MIF family of zeolites, the crystal lattice of which consists of silicon oxide and aluminum oxide in a molar ratio of silicon oxide to aluminum oxide which is greater than 20 and less than 500, and is comprised of crystallites, at least 90% of which have diameters smaller than 500 .ANG..