This disclosure provides for new catalyst systems and new methods for preparing and using the catalyst systems for generating a trimerization product. In an aspect, the new catalyst systems comprise a chromium carboxylate that is prepared by anhydrous metathesis. In another aspect, the catalyst system comprise a chromium carboxylate that is prepared by anhydrous metathesis and a metal pyrrolide compound. The catalyst systems imparts improved performance and/or reduced catalyst system cost to an olefin trimerization process.