The present invention relates to catalyst components for the polymerization of olefins comprising Mg, Ti, halogen and at least two electron donor compounds, said catalyst component being characterized by the fact that at least one of the electron donor compounds, present in an amount from 20 to 50% by mol with respect to the total amount of donors, is selected from esters of succinic acids which are not extractable, for more than 25% by mol and at least another electron donor compound which is extractable, for more than 35%. The said catalyst component are capable to give polymers with high xylene insolubility, high stereoblock content and broad MWD suitable for making the polymers usable in the BOPP sector.