  As an extension of our previous work in the seesaw mechanism, we analyze the
influence of $U_{e3}$ on the properties (masses and mixing) of the RH Majorana
neutrinos in three flavors. The quasidegenerate light neutrinos case is also
considered. Assuming the hierarchical Dirac neutrino masses, we find the heavy
Majorana neutrino mass spectrum is either hierarchical or partial degenerate if
$\theta_{23}^{\nu}$ is large. We show that degenerate RH Majorana masses
correspond to maximal RH mixing angle while hierarchical ones correspond to the
RH mixing angles which scale linearly with the mass ratios of the Dirac
neutrino masses. An interesting analogue with the behavior of the
matter-enhanced neutrino conversion is also presented.
