A process for the polymerization of an olefinic monomer by contacting the monomer with a polymerization initiator having an oxidizing agent, a chelating compound of the metal, in which the metal is still capable of accepting one or more electron pairs from an electron donor and an electron donor in an amount at least equal to that required to complex completely the metal of the chelate compound. With the polymerization initiator, polymerization of the olefinic monomer can be accomplished at low temperatures employing oxidizing agents which are stable at the lower temperatures. Also, the solubility of the initiators allows polymerization by suspension process.