  We study variations of the standard leptogenesis scenario that can arise if
an additional mass scale related to the breaking of some new symmetry (as for
example a flavor or the B-L symmetry) is present below the mass $M_{N_1}$ of
the lightest right-handed Majorana neutrino. Our scheme is inspired by U(1)
models of flavor \`a la Froggatt-Nielsen, and involves new vectorlike heavy
fields $F$. We show that depending on the specific hierarchy between $M_{N_1}$
and the mass scale of the fields $F$, qualitatively different realizations of
leptogenesis can emerge. We compute the CP asymmetries in $N_1$ decays in all
the relevant cases, and we conclude that in most situations leptogenesis could
be viable at scales much lower than in the standard scenario.
