We report the first electron paramagnetic resonance studies of single crystals and powders of Pr_0.6Ca_0.4MnO₃ in the 300-4.2 K range, covering the charge-ordering transition (T_co) at ~240 K and antiferromagnetic transition (T_N) at ~170 K. The asymmetry parameter for the Dysonian single-crystal spectra shows an anomalous increase at T_co. Below T_co the g-value increases continuously, suggesting a gradual strengthening of the orbital ordering. The linewidth undergoes a sudden increase at T_co and continues to increase down to T_N. The intensity increases as the temperature is decreased until T_co is reached, due to the renormalization of the magnetic susceptibility arising from the build-up of ferromagnetic correlations.