A catalyst composition, a process for producing the composition and a hydrocarbon conversion process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises a zeolite having impregnated thereon a activity promoter selected from the group consisting of molybdenum, molybdenum oxides, lanthanum, lanthanum oxides, and combinations of two or more thereof. The composition can be produced by incorporating the activity promoter into the zeolite. The hydrocarbon conversion process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.