Abstract: The invention relates to a flame-retarded polyester composition comprising 20-95 mass % aromatic polyester; 4-25 mass % bromine-containing flame-retardant compound; 1-12 mass % antimony oxide of average particle size 0.5-15 micron; and optionally polytetrafluoroethylene; glass fibers; and other additives. The composition shows a desirable combination of high strength and toughness, good melt-flow characteristics, no blooming and can be laser-marked with improved contrast. The invention also relates to a molded part for use in electrical or electronic applications, which part may be provided with a dark marking on a lighter background surface. The invention also relates to a process for applying a laser mark, as well as to an article carrying a dark laser mark on a light background surface for use in electrical or electronic applications.