The invention concerns the use as a thickening agent, in possibly pigmented aqueous formulations, such as coating formulations such as paints in the aqueous phase such as dispersion paints, varnishes, paper coatings, cosmetic formulations, detergent formulations, textile formulations and drilling muds, of a water-soluble acrylic copolymer consisting of at least one monomer with ethylenic unsaturation and a carboxylic function, at least one non-ionic monomer with ethylenic unsaturation, at least one oxyalkylated monomer with ethylenic unsaturation terminated by a hydrophobic branched and non-aromatic chain with 10 to 24 carbon atoms, and possibly at least one monomer with at least two ethylenic unsaturations.The invention also concerns the possibly pigmented aqueous formulations obtained.