The present disclosure provides a solid catalyst component obtainable by a process including: (a) a first step in which Ti(OEt)4, is reacted with a Mg based compound of formula MgCln(ORI)2-n, where n is from about 0.5 to about 1.5, RI is a C1-C10 alkyl groups, the Ti(OEt)4 and the Mg compound are used in amounts such that the Ti/Mg molar ratio is of about 0.2 to about 0.4, the reaction temperature is about 110 to about 130° C., and the reaction time is about 2 to about 5 hours; and (b) a subsequent step in which the product obtained in step (a) is reacted with a Ti compound of the formula Ti(ORI)4-yCly, where y is a number between 3 and 4.