A process for producing ethylbenzene or cumene comprising the steps of: (a) providing an transalkylation catalyst composition to a reaction zone, said transalkylation catalyst comprising a zeolite having a framework structure selected from the group consisting of FAU, BEA ∗ , MOR, MWW and mixtures thereof, wherein the silica-alumina molar ratio of said zeolite is in a range of 10 to 15, wherein said transalkylation catalyst composition is in the form of an extrudate having an external surface area/volume ratio in the range of 40 cm -1 to 85 cm -1 ; (b) providing a stream comprising a poly-alkylated benzene and a portion of an alkylatable aromatic compound stream to said reaction zone, wherein said poly-alkylated benzene stream comprises di-ethylbenzene or di-isopropylbenzene and said alkylatable aromatic compound stream comprises benzene; (c) contacting said poly-alkylated benzene stream with said alkylatable aromatic compound stream in the presence of said transalkylation catalyst composition under at least partial liquid phase transalkylation conditions to alkylate the alkylatable aromatic compound and produce a transalkylation effluent stream comprising ethylbenzene or cumene; (d) providing a stream comprising an alkylating agent and another portion of said alkylatable aromatic compound stream to another reaction zone; (e) contacting said another portion of said alkylatable aromatic compound stream with said stream comprising an alkylating agent under alkylation conditions in the presence of an alkylation catalyst to alkylate the alkylatable aromatic compound and produce an alkylation effluent stream which comprises mono-alkylated benzene and said poly-alkylated benzene; (f) separating said alkylation effluent stream to recover said poly-alkylated benzene stream; and (g) supplying at least a portion of said poly-alkylated benzene stream to step (b). (a) providing an transalkylation catalyst composition to a reaction zone, said transalkylation catalyst comprising a zeolite having a framework structure selected from the group consisting of FAU, BEA ∗ , MOR, MWW and mixtures thereof, wherein the silica-alumina molar ratio of said zeolite is in a range of 10 to 15, wherein said transalkylation catalyst composition is in the form of an extrudate having an external surface area/volume ratio in the range of 40 cm -1 to 85 cm -1 ; (b) providing a stream comprising a poly-alkylated benzene and a portion of an alkylatable aromatic compound stream to said reaction zone, wherein said poly-alkylated benzene stream comprises di-ethylbenzene or di-isopropylbenzene and said alkylatable aromatic compound stream comprises benzene; (c) contacting said poly-alkylated benzene stream with said alkylatable aromatic compound stream in the presence of said transalkylation catalyst composition under at least partial liquid phase transalkylation conditions to alkylate the alkylatable aromatic compound and produce a transalkylation effluent stream comprising ethylbenzene or cumene; (d) providing a stream comprising an alkylating agent and another portion of said alkylatable aromatic compound stream to another reaction zone; (e) contacting said another portion of said alkylatable aromatic compound stream with said stream comprising an alkylating agent under alkylation conditions in the presence of an alkylation catalyst to alkylate the alkylatable aromatic compound and produce an alkylation effluent stream which comprises mono-alkylated benzene and said poly-alkylated benzene; (f) separating said alkylation effluent stream to recover said poly-alkylated benzene stream; and (g) supplying at least a portion of said poly-alkylated benzene stream to step (b). <EOS>