  We point out that dissociation of J/Psi by partons (mostly gluons) present in
the intermediate stage of heavy-ion collisions can explain J/Psi suppression
observed recently by the NA-50 Collaboration at the CERN-SPS in Pb-Pb
interactions. Suppression by intermediate stage gluons represents an additional
multiplicative factor to that given by Gerschel-Hufner mechanism. The agreement
with data on J/Psi suppression both in light- ions induced nuclear collisions
and in Pb-Pb interactions requires that the life-time of intermediate gluons
increases with nucleon numbers of colliding nuclei. In our model the energy
density of intermediate stage gluons in Pb-Pb collisions approaches for a short
time the critical density.
