The invention relates to flame-retardant polyester compounds comprising as component A 40% to 89.9% by weight of thermoplastic polyesters, as component B 5% to 25% by weight of phosphinic salt of the formula (V) and/or diphosphinic salt of the formula (VI) and/or polymers thereof, in which R1 and R2 are H or C1-C6-alkyl and/or aryl; R3 is C1-C10-alkylene, C6-C10-arylene, -alkylarylene or -arylalkylene; M is Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K and/or a protonated nitrogen base; m is 1 to 4; n is 1 to 4; and x is 1 to 4, and as component C 5% to 25% by weight of a phosphazene, as component D 0% to 15% by weight of reaction products of melamine with phosphoric acid and/or condensed phosphoric acids, as component E 0% to 45% by weight of reinforcing agents, and as component F 0.1% to 3% by weight of further additives, the sum of the components by weight being 100% by weight.