(57) A laundering agent is provided which contains active detergent, builders, a combination of polyphosphate with zeolite as sequestering agent and, if desired, further usual additives, wherein the sequestering effect of the polyphosphate-zeolite combination is enhanced by an ethercarboxylic acid of the formula RO-(C₂H₄O)_x-CH₂COOM or R-CO-NH-(C₂H₄O)_x-CH₂COOM, wherein R is the residue of an aliphatic or alkyl aromatic hydrocarbon having at least 8 carbon atoms, x is a number having an average value of 0.5-20 and M is hydrogen or a cation permissible in laundering agents, said polyether carboxylic acid being present in an amount of 0.3-10%, preferably 0.3-5%, based on the entire composition.