Phenomenological implications of the Z' in SU(3) x SU(3) x U(1) extens
ion of the standard model are studied. We find that the current experi
mental value of R-b puts severe constraints on the Z' mass in this mod
el. The model improves slightly the fit for large E-T jet cross sectio
n observed by CDF. (C) 1997 Published by Elsevier Science B.V.