  Production of open and hidden charm hadrons in heavy ion collisions is
considered within the statistical coalescence model. The charmed
quark-antiquark pairs are assumed to be created at the initial stage of the
reaction in hard parton collisions. The number of these pairs is conserved
during the evolution of the system. At the hadronization stage, the charmed
(anti)quarks are distributed among open and hidden charm hadrons in accordance
with the laws of statistical mechanics.
  The model is in agreement with the experimental data on J/psi to Drell-Yan
ratio in Pb+Pb collisions at SPS. This agreement can be reached only if a
rather strong enhancement of the open charm production in central Pb+Pb
collisions is assumed. A possible mechanism of the charm enhancement is
discussed.
  At the top RHIC energy, the model predicts an increase of J/psi to Drell-Yan
ratio in more central nucleus-nucleus collisions with respect to less central
ones.
