| abstract |
A catalytic composition for oligomerizing olefins, in particular ethylene, comprises mixing at least one nickel complex, prepared by reacting a nickel salt with a phosphonite ligand, with at least one hydrocarbylaluminum compound in a small proportion with respect to the nickel and selected from the group formed by tris(hydrocarbyl)aluminum compounds, chlorinated or brominated hydrocarbylaluminum compounds and aluminoxanes. |