Leptophobic U(1)'s and R_b, R_c at LEP

In the context of explaining the experimental deviations in R_b and R_c from their Standard Model predictions, a new type of U(1) interaction is proposed which couples only to quarks. Special attention will be paid to the supersymmetric \eta-model coming from E_6 which, due to kinetic mixing effects, may play the role of the leptophobic U(1). This talk summarizes work done with K.S. Babu and J. March-Russell in hep-ph/9603212.