FIELD: organic synthesis catalysts. SUBSTANCE: composition is based on beta-zeolite as it is or modified by isomorphous substitution of aluminum by boron, iron or gallium or modified by ion exchange-mediated introduction of alkali and/or alkali-earth metals, said catalytic composition having extrazeolite porosity, that is summary meso- and macroporosity, such that its fraction at least 25% is constituted by pores with radius larger than 
whereas full volume of extrazeolite pores of catalyst is equal to at least 0.8 ml/g. This catalytic composition is used to alkylate and/or realkylate aromatic hydrocarbons and to produce monoalkylated aromatic hydrocarbons. EFFECT: increased catalytic activity. 27 cl, 1 tbl, 13 ex
