Complex [Ti(?2-N,O-{2,6-F2C6H3N?C(Me)C(H) ?C(CF3) O})2Cl2] (1) was evaluated as catalyst for living copolymerization of ethylene (E) with norbornene (N) upon activation with dried methylaluminoxane (d-MAO) at temperatures between 25 and 90 degrees C. Copolymerization performed at different [N]/[E] feed ratios afforded stereoirregular alternating high molar mass P(E-co-N) with narrow molar mass distribution. The living nature of E-co-N copolymerization by 1/d-MAO was demonstrated by kinetics at 50 degrees C. This catalyst system was used for the synthesis of block copolymers such as polyethylene (PE)-block-P(E-co-N) with a crystalline PE block and an amorphous P(E-co-N) block as well as P(E-co-N)1-block-P(E-co-N)2, having different norbornene contents in the segments and thus having different Tg values. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012