US Patent 7285513 Preparation of catalyst systems

The present invention relates to a process for preparing a catalyst for olefin polymerization which is obtainable by bringingA) at least one organic transition metal compound,B) a mixture of at least two different organo metallic compounds andC) at least one cation-forming compoundinto contact with one another, wherein the organic transition metal compound A) is firstly brought into contact with the mixture of the organo metallic compounds B). In addition, the invention relates to the use of the catalyst for olefin polymerization, to catalysts obtainable by this process and to a process for the polymerization of olefins in which these catalysts are used.