We investigated the effect of superelastic electronic collisions of electrons, with the c 3 Π u state of the H 2 molecule, on the electron energy distribution function (eedf) of a dc positive column. We use a recently calculated set of electronic superelastic collision cross-sections [C.S. Sartori, F.J. da Paixão, M.A.P. Lima, Phys. Rev. A 55 (1997) 3243] to study the effect of these collisions on the eedf, the transport parameters, ionization and dissociation rates. We include two possible pathways, c 3 Π u → b 3 Σ + u and c 3 Π u → X 1 Σ + g , for superelastic collisions of electrons with molecules in the metastable state. Cross-sections of the order of 10 −14 cm 2 at low energy enhance the eedf tail by superelastic electronic collisions, in particular for low reduced electric field E/ N. This result changes considerably the dissociation and ionization rates by six orders of magnitude in the region from 10 to 50 Td.