  We discuss an extended SU(2)XU(1) model which naturally leads to mass scales
and mixing angles relevant for understanding both the solar and atmospheric
neutrino anomalies in terms of the vacuum oscillations of the three known
neutrinos. The model uses a softly broken L_e-L_{\mu}-L_{\tau} symmetry and
contains a heavy scale M_H\sim 10^{15} GeV. The L_e-L_{\mu}-L_{\tau} symmetric
neutrino masses solve the atmospheric neutrino anomaly while breaking of
L_e-L_{\mu}-L_{\tau} generates highly suppressed radiative mass scale
\Delta_S\sim 10^{-10} eV^2 needed for the vacuum solution of the solar neutrino
problem. All the neutrino masses in the model are inversely related to M_H,
thus providing seesaw-type of masses without invoking any heavy right-handed
neutrinos. Possible embedding of the model into an SU(5) grand unified theory
is discussed.
