Poly(butylene terephthalate) based molding resins

A flame retardant molding resin capable of being molded into an article exhibiting reduced tendency to corrode a copper surface when the molded resin and the copper surface are placed in spaced relationship in a common unventilated atmosphere at elevated temperatures, as measured by the Bell Telephone Laboratories Copper Corrosion Test at temperatures within the range of from 150.degree. to 175.degree. C., wherein the molding resin comprises the combination of (a) a butylene terephthalate polyester comprising a brominated copolyester as a polymeric flame retardant comprising aromatic halogen groups in a flame retardant amount, and (b) an alkylhydroxyphenylalkanoyl-hydrazine in an amount that is within the range of from 0.05 to 0.3% by weight, based on the weight of the molding resin, and wherein the molding resin does not contain any phenolic antioxidant that is free of nitrogen and the molding resin has a life of at least 60 hours at 175.degree. C. as measured by the Bell Test based on 3 samples.