Abstract: A catalyst composition for polymerising ethylene with a superior activity, productivity, and giving, in particular, copolymers with an improved narrower short chain branching distribution, and especially an improved cling development in PIB formulated films. The catalyst composition for the (co-)polymerisation of ethylene, optionally with an alpha olefin of 3 to 10 carbon atoms, has a catalyst precursor and an organoaluminium cocatalyst, wherein the catalyst precursor has i) a catalyst carrier material, having from 0.3 to 1.2 mmoles of OH groups per gram of catalyst carrier; ii) a dialkylmagnesium compound of the formula RMgR1, where R and R1 are the same or different C2-C12 alkyl groups, in an amount between 1.1 and 2.4 mmoles of diakylmagnesium per gram of catalyst carrier; iii) a tetraalkyl orthosilicate, in which the alkyl group contains from 2 to 6 carbon atoms, in an amount between 0.4 and 1.

Abstract: The present invention relates to a process for the preparation of a solid catalytic component of a catalyst of Ziegler-Natta type, comprising contacting (i) at least one compound (A) of a transition metal (TM) with (ii) a solid product (B) comprising a magnesium compound and having a reducing power for the transition metal (TM), in the presence of (iii) at least one olefin under conditions such that the olefin at least partially polymerizes during the contacting. The solid catalytic component is particularly useful for producing ethylene (co-)polymers in a gas phase process and for improving the statistical distribution of the comonomer in the copolymer structure.