Catalyst components for polymerization of olefins

A catalyst composition for use in the manufacture of polyolefins which is comprised of a first component (I) and a second component (II), where said first component (I) is a reaction product of reaction compounds consisting essentially of:

• a compound (i) of formula
• Me.sup.1 R.sub.4.sup.1
• wherein R.sup.1 is selected from the group consisting of an alkyl, alkenyl, aryl, alkoxy, aryloxy, and aralkyloxy moiety of 1-24 carbon atoms, and Me.sup.1 is zirconium or hafnium;
• a compound (ii) of the formula
• Me.sup.2 R.sub.m.sup.2 X.sub.z-m.sup.2
• wherein R.sup.2 is a hydrocarbon group of 1-24 carbon atoms, X.sup.2 is a halogen atom, Me.sup.2 is an element of Group III in the Periodic Table, z is the valence of Me.sup.2, and m is a number such that 0.ltoreq.m.ltoreq.3;
• a cyclic hydrocarbon (iii) having two or more conjugated double bonds;
• and
• a carrier (iv) selected from the group consisting of inorganic carriers, particulate polymer carriers and mixtures thereof;
• said second component (II) being a modified organoaluminum compound having at least one Al--O--Al bond derived from the reaction of an organoaluminum compound and water.