We report the complete C-13 NMR characterization of a series of ethylenepropylene-1-hexene terpolymers obtained with the metallocenic system rac-ethylene bis-indenyl zirconium dichloride, with different comonomer ratios. A detailed study of C-13 NMR chemical shifts, triad sequence distributions, monomer-average sequence lengths, and reactivity ratios for these terpolymers is presented. (C) 2004 Wiley Periodicals, Inc.