To obtain a thermoplastic composition by mixing a ground vulcanized rubber with a polyolefin resin and a functionalized olefin polymer being a copolymer of an olefin with an ethylenically unsaturated organic monomer.

1-90 pts.wt. dispersed particulate ground vulcanized rubber having a particle diameter of 1.5 μm or below and selected among natural rubbers and alkadiene polymer or copolymer rubbers is compounded with 90-1 pts.wt. polyolefin resin selected among PE, PP, etc. The obtained compound is added with at least 0.5 pt.wt., per 100 pts.wt. polyolefin resin, functionalized olefin polymer being a copolymer of an olefin with an ethylenically unsaturated monomer (selected among 3-20C unsaturated mono- or di-carboxylic acid, acid anhydrides, etc., vinyl esters of saturated carboxylic acids having 2-18 acid groups, etc., and vinyl alkyl ethers with a 1-18C alkyl), a phenolic resin, and a suitable amount of additives, and the resulting compound is kneaded at about 140-200°C to obtain a thermoplastic composition having good mechanical properties.