[en] Mixture of two catalysts in one reactor for ethylene/α-olefin copolymerization results in the combination of properties of both catalysts, and thus the synthesis of a novel polymer microstructure characterized by sequences of monomers produced with each catalyst. Adding a reversible transfer agent (CSA) to the binary system enables the production of new block copolymers with enhanced properties. Late transition metal catalysts, such as α-diimine nickel catalyst when activated with MAO show high activity towards olefin polymerization. This paper describes the syntheses of PE with amorphous and crystalline blocks using a binary mixture containing a nickel catalyst with α-diimine ligand which produces highly branched polyethylene (soft PE) and a metallocene (rac-ethylenebis(H₄-indenyl)ZrCl₂) that converts ethylene into polyethylene with high activities and melting temperatures (hard PE). The influence of polymerization temperature and CSA concentration were investigated. The polymeric materials were characterized by density, thermal properties and X-ray diffractometry. (author)