The present invention relates to a process for preparing a polyetherol which comprises reacting at least one alkylene oxide with at least one starter compound in the presence of a catalyst of the formula I: M.sup.1.sub.p[M.sup.2.sub.qO.sub.n(OH).sub.2(3-n)].sub.x, (I) and to the polyetherols prepared by such a process and to their use for the synthesis of polyurethanes, as fuel additive or as surfactant.