A composition comprising a source of metal ions and at least one leveling agent obtainable by condensing at least one trialkanolamine of the general formula N(R1—OH)3 (Ia) and/or at least one dialkanolamine of the general formula R2—N(R1—OH)2 (Ib) to give a polyalkanolamine(II), wherein the R1 radicals are each independently selected from a divalent, linear or branched aliphatic hydrocarbon radical having from 2 to 6 carbon atoms, and the R2 radicals are each selected from hydrogen and linear or branched aliphatic, cycloaliphatic and aromatic hydrocarbon radicals having from 1 to 30 carbon atoms, or derivatives obtainable by alkoxylation, substitution or alkoxylation and substitution of said polyalkanolamine(II).