Process for the co-production of acetic acid and dimethyl ether products from a mixture of methanol and methyl acetate by contacting the mixture at a temperature from 200 to 260° C., with a catalyst composition containing a zeolite possessing a 2-dimensional channel system. The catalyst system contains at least one channel having a 10-membered ring and a silica:alumina molar ratio of at least 22:1.