-1- of the disclosure Bulk polymerization using specific metallocene catalysts for the preparation of cycloolefin polymers Polymers of polycyclic olefins, such as, for example, norbornene or tetracyclododecene, or copolymers of polycyclic olefins with cycloolefins and/or 1-olefins are obtained without ring opening, in high space-time yield, with a high cycloolefin incorporation rate and at in- dustrially favorable polymerization temperatures, by bulk polymerization in which a catalyst is used which comprises an aluminoxane and a stereorigid chiral metal- locene compound of an element from groups IVb to VIb, where the hydrocarbon radicals forming the sandwich structure are different.