Abstract: Polyester fibers containing one or more oxalate complexes of the general formulaMe.sub.n [Z(C.sub.2 O.sub.4).sub.m ]are drawn and subjected to a hydrosetting process at temperatures of 90.degree. to 170.degree. C. in the presence of liquid water, the water containing one or more of the following surfactants: salts of partial esters of phosphoric aid, sulfosuccinic aid esters, phosphonic acid esters as well as ethoxylated silicon compounds, ethoxylated fatty alcohols, polyglycol esters of fatty acids as well as various imidazole salts of partially or completely hydrogenated imidazoles. In this way the hydrosetting process is accelerated and a more stable pore structure is obtained. Water absorption and retention are also increased.