  We propose an extension of the standard model with a B-L global symmetry that
is broken softly at the TeV scale. The neutrinos acquire masses through a
type-II seesaw while the lepton (L) asymmetry arises in the {\it singlet
sector} but without B-L violation. The model has the virtue that the scale of
L-number violation ($\Lambda$) giving rise to neutrino masses is independent of
the scale of leptogenesis ($\Lambda'$). As a result the model can explain {\it
neutrino masses, singlet scalar dark matter and leptogenesis at the TeV scale}.
The stability of the dark matter is ensured by a surviving $Z_2$ symmetry,
which could be lifted at the Planck scale and thereby allowing Planck
scale-suppressed decay of singlet scalar dark matter particles of mass $\approx
3$ MeV to $e^+ e^-$ pairs in the Galactic halo. The model also predicts a few
hundred GeV doubly charged scalar and a long lived charged fermion, whose decay
can be studied at Large Hadron Collider (LHC) and International Linear Collider
(ILC).
