  We show how the problem of small neutrino masses and suppressed proton decay
can be simultaneously resolved in 6-D universal extra dimension models (UED)
with a low fundamental scale using extended gauge groups that contain the local
$B-L$ symmetry. The extra space dimensions are compactified either on a
$T^2/Z_2$ or $T^2/Z_2\times Z'_2$ orbifold depending on whether the full gauge
group is $SU(2)_L\times U(1)_{I_{3R}}\times U(1)_{B-L}$ or $SU(2)_L\times
SU(2)_{R}\times U(1)_{B-L}$. In both cases, neutrino masses are suppressed by
an appropriate orbifold parity assignment for the standard model singlet
neutrinos and the proton decay rate is suppressed due to a residual discrete
symmetry left over from compactification. For lower values of the fundamental
scale, a dominant decay mode of the neutron is $n\to 3 \nu$. An interesting
consequence of the model is a possible two component picture for dark matter of
the universe.
