An oligomerization process comprising reacting an olefin feed comprising at least one olefin with a catalyst and a cocatalyst under oligomerization conditions to form an olefin product:wherein the catalyst is represented by the formula RC(YR')2 !2 CrX, wherein R and R' are individually selected from the group consisting of carbyl and carbylsilyl groups; Y is N, C or P; and X is a halogen, halogen