The results of radical ter-polymerization of maleic anhydride (MA), dicyclopentadiene (DCPD) and vinyl ter-co-monomers (vinyl acetate-VA, or butyl-vinyl ether-BVE) are discussed. The original objective was to obtain higher molecular weights, than the usual bi-component MA-DCPD copolymers. Some peculiar kinetic features have been put into evidence.