Patent ID: 7081557

Claim:
A process for the oligomerization of olefins in which an olefin is brought into contact with a catalyst system which is obtained from a) at least one chromium source; b) at least one ligand of the formula I where R 1 to R 3 are each, independently of one another, a radical of the formula II or C 1 - to C 8 -alkyl; R A are each, independently of one another, an organic group having from 1 to 30 carbon atoms which is bound via a silicon atom or a carbon atom, with the proviso that at least one of the radicals R 1 , R 2 , R 3 and R A is a radical of the formula II; p is from 0 to 6; m is from 1 to 6; n is from 2 to 6; and c) at least one activator.