A catalyst composition comprises (a) a MCM-22 family molecular sieve; and (b) a binder, wherein the MCM-22 family molecular sieve is characterized by an average crystal agglomerate size of less than or equal to 16 microns. The catalyst composition may further have a second molecular sieve having a Constraint Index of less than 12, e.g., less than 2. Examples of molecular sieve useful for this disclosure are a MCM-22 family molecular sieve, zeolite Y, and zeolite Beta. The catalyst composition may be used for the process of alkylation or transalkylation of an alkylatable aromatic compound with an alkylating agent.