Polymer blend composition

A thermoplastic molding composition comprising:

• (a) from about 10 to about 85 percent by weight of a selectively hydrogenated block copolymer comprising at least two monoalkenyl arene polymer end blocks A and at least one substantially completely hydrogenated conjugated diene polymer mid block B, the weight percent of blocks A comprising between 8 and 65 percent by weight of said block copolymer wherein at least 80% of the aliphatic double bonds in block B are hydrogenated and no more than about 25% of the alkenyl aromatic double bonds in blocks A are hydrogenated;
• (b) from about 10 to about 80 percent by weight of a vinyl aromatic copolymer comprising a vinyl aromatic compound and an .alpha., .beta.-unsaturated cyclic anhydride;
• and
• (c) from about 10 to about 80 percent by weight of a thermoplastic polyester having a molecular weight in excess of about 20,000, a melting point over about 120.degree. C., and which polyester is selected from the group consisting of a condensation product of a dicarboxylic acid and a glycol, polypivalolactone and polycaprolactone.