Abstract: The invention relates to a process for the condensation of compounds which carry silanol groups and have at least one unit of the general formula (III) AcEdSiO(4-c-d)/2  (III) in which A is a hydroxyl group, E is an inert radical, c is 1, 2, 3 or 4 and d is 0, 1 or 2, with the proviso that c+d ≦4, in which higher molecular weight organosiloxane compounds are prepared by employing with a catalyst system comprising a catalyst which is chosen from basic alkali metal and alkaline earth metal compounds and a cocatalyst which is an at least bidentate chelating ligand and contains units of the general formula (I) N—R1—N  (I)  in which R1 is a divalent linear, cyclic and/or aromatic C1-to C30-hydrocarbon radical.