  We present a complete set of generators for the rank 5 special unitary group,
SU(6), to unify strong, weak and electromagnetic interactions. The unification
is realized through the breaking pattern of SU)6) -> SU(3)_C x SU(3)_H x U(1)_C
followed by SU(3)_H -> SU(2)_L x U(1)_B. All known elementary particles and its
quantum numbers are well accomodated in its {6} and {15} multiplets. These
multiplets require a new neutral fermion which should be assigned as the heavy
Majorana neutrino to realize the seesaw mechanism naturally in the minimal
scenario of this model.
