  We examine one simple mechanism which leads to approximate maximal $\nu_\mu -
\nu_\tau$ oscillations in the standard see-saw model. In particular, we show
that this scheme could be implemented in the Exact Parity Model (also known as
the mirror matter model). Within this framework the solar neutrino problem is
solved by maximal $\nu_e \to \nu'_e$ oscillations (with $\nu'_e$ is the
essentially sterile mirror partner of $\nu_e$) and the LSND evidence for $\nu_e
\to \nu_\mu$ oscillations can also be explained.
