An olefin polymerization process wherein monomer, at least one olefin comonomer different from the olefin monomer, diluent and catalyst are circulated in a continuous loop reactor and product slurry is recovered by means of a continuous product take off. The continuous product allows operating the reaction at significantly higher solids content in the circulating slurry. The polymerization process operates at a space-time yield of at least 2.18 lb/hr-gal.