The present invention relates to a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof, that are esterified with an alcohol, or mixtures thereof, and wherein at least a portion of carboxylic acid groups not esterified react with an amine. The invention further provides for a lubricating composition containing said copolymer. The invention further provides a method and use of lubricating composition in a mechanical device.