Polyester multifilament yarn and a process for manufacturing the same

A polyester multifilament yarn consisting essentially of:

• a filament group (I) comprised of at least one polyester selected from the group consisting of polyethylene terephthalate polytrimethylene terephthalate polytetramethylene terephthalate blends thereof and copolymers comprising at least two members selected from said polyesters;
• and a filament group (II) comprised of a polyester substrate selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, blends thereof and copolymers comprising at least two members selected from said polyesters and from about 0.4 to 8% by weight based on the substrate of at least one polymer selected from the group consisting of styrenic polymers, methacrylate polymers and acrylate polymers added to said substrate wherein the average breaking elongation of filaments of the filament group (II) is larger than the average breaking elongation of filaments of the filament group (I) and wherein the average denier of constituent filaments of said filament group (I) is at least equal to the average denier of constituent filaments of said filament group (II).