Metal complex containing one or more silsesquioxane ligands

Process for the polymerization of olefins, comprising contacting the olefin with a metal complex having the formula Zy(MAx)b, wherein

• Z is a silsesquioxane ligand of formula (II):
• (RSiO1.5)mOnBq (II)
• and is connected wish one corner where a Si-atom is not present to two M atoms by one bridging oxygen atom, wherein the bridging oxygen atom is from the silsesquioxane or formula (II),
• M is a metal from groups 3-10 of the Periodic System of the Elements and the lanthanides,
• A is a hydrocarbon substitutent containing 1-20 carbon atoms covalently bonded to the metal,
• y represents the number of silsesquioxane ligands and is 2-10,
• b represents the number of metal groups and is 2-20,
• x is the number of substituents A bonded to the metal,
• the value of x depending on the metal used and is equal to the valency of the metal minus 1, 2, 3 or 4,
• R is a substituent bonded to each Si,
• m is an integer and is equal to 5-19,
• q is 1, 5 or 3,
• B is a group bonded to an oxygen atom that has one bond to Si, and
• q is 0, 1 or 2.