An alkylating process for the production of at least one of 2-, 3-, 4-, 5-, and 6-phenylalkanes by alkylation of an aromatic compound with a feedstock containing at least one olefin comprising at least 9 carbon atoms per molecule, in the presence of a catalyst comprising at least one substrate based on at least a zeolite and a non-zeolitic silica-alumina matrix with a low content of macropores, whereby said matrix contains an amount of more than 5% by weight and less than or equal to 95% by weight of silica (SiO.sub.2), whereby said process is carried out at a temperature of between 30 and 400.degree. C., a pressure of between 0.1 and 10 MPa, an hourly volumetric flow rate of 0.50 to 200 h.sup.-1, and an aromatic compound/olefin molar ratio of between 1:1 and 50:1.