  We explore the idea that dark matter stability results from the presence of a
matter-parity symmetry, arising naturally as a consequence of the spontaneous
breaking of an extended $\mathrm{SU(3) \otimes SU(3)_L \otimes U(1)_X \otimes
U(1)_{N}}$ electroweak gauge symmetry with fully gauged B-L. Using this
framework we construct a theory for scotogenic dark matter and analyze its main
features.
