The invention relates to compatible PM polymer blends with polyesters as mix components, which compriseA) 0.1 to 99.9 wt % of a P1 polyester synthesized from units of formula I ##STR1## where R stands for a group --(CH.sub.2).sub.m -- or for a group ##STR2## and where m stands for a number from 2 to 6, andB) 99.9 to 0.1 wt % of a P2 polyester synthesized to 20-100 wt % from halogen-free monomers of formula II ##STR3## where R.sub.1 stands for hydrogen or methylR.sub.2 stands for a spacing group having 1-6 monomers,R.sub.3 stands for an alkyl group, alkoxy group or aminoalkyl- or dialkyl group having 1 to 6 carbon atoms andq stands for zero or one andz stands for zero, one or two.