  We study a seesaw-type extension of the Standard Model in which the symmetry
group is enlarged by a global U(1). We introduce adequate scalar and fermion
representations which naturally explain the smallness of neutrino masses. With
the addition of a viable scalar Dark Matter candidate, an original scenario of
leptogenesis emerges. We solve the relevant set of Boltzmann equations and show
how leptogenesis can be successfully implemented at the TeV scale. The
constraints on the scalar mass spectrum are derived and the Dark Matter
phenomenology is discussed.
