Process to prepare a solid support for a procatalyst for polymerization of olefins

A process for the preparation of a solid support for a procatalyst suitable for preparing a catalyst composition for olefin polymerization, said process comprising:

• A) providing or preparing a compound R4zMgX42-z wherein:
• R4 is independently a linear, branched or cyclic hydrocarbyl group independently selected from alkyl, alkenyl, aryl, aralkyl, or alkylaryl groups, or one or more combinations thereof;
• X4 is independently fluoride, chloride, bromide or iodide;
• and 0<z<2;
• and
• B) contacting the compound R4zMgX42-z with a silane compound Si(OR5)4-n(R6)n to form a Mg(OR1)xX12-x wherein:
• R1, R5 and R6 are each independently a linear, branched or cyclic hydrocarbyl group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, or one or more combinations thereof;
• X1 is independently fluoride, chloride, bromide or iodide;
• n is in range of 0 to 4;
• 0<z<2;
• and 0<x<2;
• wherein an initiator compound, which is a ketone, a diketone, an ester, a diester, or a benzamide, is added during step B to obtain a solid support,
• wherein the initiator compound does not contain any heteroatom, nor is a phthalate.