Process for obtaining aromatic oils having a polycyclic aromatic compounds content of less than 3 %, useful as rubber extenders, from the mixed extract flow obtained in the manufacture of lubricant bases, which comprises cooling the flow of mixed extracts to render non-polyaromatic components insoluble, settling to bring about separation of the bases, total or partial redissolution in solvent of the light phase obtained in said settling, cooling to effect separation of the non-polyaromatic components, and settling to recover the light phase having a low polyaromatic compound content. A hydrocarbonated stream, having an initial boiling point greater than 200°C, to regulate the solvent/solute rate and increase the production capacity of aromatic oils with a PCA content of less than 3%, may be added to the starting mixed extract flow.