must not be greater than that which can be deposited onto the support if greater than that amount is added to the solvent the excess may react with the non metallocene transition metal compound thereby forming a precipitate outside of the support which is detrimental in the synthesis of our catalyst and must be avoided the amount of the organomagnesium compound which is not greater than that deposited onto the support can be determined in any conventional manner e g by adding the organomagnesium compound to the slurry of the carrier in the solvent while stirring the slurry until the organomagnesium compound is detected in the solvent for example for the silica carrier heated at about 600 u00b0 c the amount of the organomagnesium compound added to the slurry is such that the molar ratio of mg to the hydroxyl groups oh on the solid carrier is about 0 5 1 to about 4 1 preferably about 0 8 1 to about 3 1 more preferably about 0 9 1 to about 2 1 and most preferably about 1 1 the organomagnesium compound dissolves in the non polar solvent to form a solution from which the organomagnesium compound is deposited onto the carrier it is also possible to add such an amount of the organomagesium compound which is in excess of that which will be deposited onto the support and then remove e g by filtration and washing any excess of the organomagnesium compound however.