  A phenomenological analysis of the three-family local gauge group
$SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ with right-handed neutrinos is carried
out. Instead of using the minimal scalar sector able to break the symmetry in a
proper way, we introduce an alternative set of four Higgs scalar triplets,
which combined with an anomaly-free discrete symmetry, produces a quark mass
spectrum without hierarchies in the Yukawa coupling contants. We also embed the
structure into a simple gauge group and show some conditions to achieve a low
energy gauge coupling unification, avoiding possible conflict with proton decay
bounds. By using experimental results from the CERN-LEP, SLAC linear collider
and atomic parity violation data, we update constraints on several parameters
of the model.
