| abstract |
The present invention relates to a process of producing an ethylene polymer composition in multiple stages, of which the first stage is preferably a slurry polymerization stage, in the presence of a catalyst system, comprising: a) a solid catalyst precursor, comprising a transition metal selected from titanium and vanadium; magnesium; a halide, optionally an electron donor; and a solid particulate material comprising an inorganic oxide, and wherein the median particle diameter, D50, of the solid catalyst precursor, based upon the total volume of solid catalyst precursor, is from 1 to 13 micrometers; and b) an organoaluminium compound. |