Zeolite catalyst for the alkylation of aromatic compounds with polyalkylated aromatic compounds

The present invention relates to a process for preparing an alkylated aromatic compound, which process comprises an alkylation reaction of an aromatic compound with an alkylating agent which is a polyalkylated aromatic compound, in the presence of a catalyst which is a porous crystalline material with a chemical composition expressed in its calcined form as X2O3:nYO2:mZO2, in which (n+m) is at least 5, X is a trivalent element, Z is Ge, Y is at least one tetravalent element other than Ge, and the n/m ratio is at least 1, said material having, in its calcined form, the characteristic X-ray diffraction pattern of Table 1.