  We study a supersymmetric E6 grand unified model in which the SU(5) 5^*
components are twisted in the third generation 27. Supplementing the adjoint
Higgs field to a model analyzed previously, we calculate the mass matrices for
the up and down quarks and charged leptons. Although the number of free
parameters is less than that of observables, an overall fitting to the observed
masses and mixing angles is shown to be possible. Most notably, we find two
novel, parameter-independent relations between the lepton 2-3 mixing angle and
the quark masses and CKM mixing angles that are in good agreement with the
large lepton mixing recently observed.
