  We study the mixing among different generations of massive neutrino fields in
a
  $SU(2)_L \times SU(2)_R \times U(1)_Y$ gauge theory which includes Majorana
and Dirac mass terms in the Yukawa sector. Parity can be spontaneously broken
at a scale $v_R\simeq 10^3-10^4$ GeV. We discuss about possible candidates for
the Yukawa coupling matrices and we found that the model can accommodate a
consistent pattern for neutral fermion masses as well as neutrino oscillations.
The left and right sectors can be connected by a new neutral current.
