  We study the effective ways for generating the linear see-saw neutrino mass
relations and large neutrino mixing angles in two classes of grand unified
SO(10) models where the texture of Dirac neutrino mass matrix is related to
either the charged lepton mass matrix (case A) or the up-quark mass matrix
(case B). We also briefly analyse their stability criteria and they are found
to be stable under under radiative corrections at low energies.
