We describe a hybrid model in which the light neutrino mass matrix receives
both tree-level seesaw and loop-induced contributions. An additional U(1) gauge
symmetry is used to stabilize the lightest right-handed neutrino as the Dark
Matter candidate. After fitting the experimental neutrino data, we analyze and
correlate the phenomenological consequences of the model, namely its impact on
electroweak precision measurements, the Dark Matter relic abundance, lepton
flavour violating rare decays and neutrinoless double beta decay. We find that
natural realizations of the model characterized by large Yukawa couplings are
compatible with and close to the current experimental limits.Comment: 25 pages, 9 figures. V2: references added, typos corrected, version
accepted by JHE