The polymerization of norbornene in the presence of ethene using the Ni(PPh3)(4)/BF3OEt2 catalyst system has been investigated. This Ni(PPh3)(4)/BF3OEt2 system is highly active for the polymerization of norbomene in the presence of ethene. The products of the reaction are norbomene oligomers with a vinytic end group, having an average polymerization degree of 9. These products are of interest as polymerizable macromonomers with high glass transition phase in thermoplastic elastomers. Ethene decreases the cocatalyst amount necessary for substantial catalytic activity compared to that needed for homopolymerization of norbornene. The nickel hydrides are likely to be catalytically active species. Ethene transformation may serve as a testing reaction for the copolymerization of norbornene with ethene in some cases. Products were characterized by NMR, IR, mass spectroscopy, GPC and GC methods. (C) 2004 Elsevier B.V. All rights reserved.