Polypropylene composition comprising: A) from 50 wt% to 90 wt%; of a propylene homopolymer having a fraction insoluble in xylene at 25 °C, higher than 90 %; and a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 0.5 to 200 g/10 min; B) from 10 wt% to 50wt%; %; of a copolymer of propylene and ethylene having from 30.0 wt% to 70.0wt%, of ethylene derived units; the sum of the amount of component A) and B) being 100; the composition having: i) an intrinsic viscosity of the fraction soluble in xylene at 25 °C comprised between 2.2 and 4.0 dl/g; ii) a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 0.5 to 100 g/10 min; iii) a xylene soluble fraction ranging from 10 wt% to 50 wt%; the polypropylene composition being obtained by a two steps polymerization process wherein: step a) propylene is polymerized to obtain component A) in the presence of a catalyst comprising the product of the reaction between: a) a solid catalyst component comprising Ti, Mg, Cl, and an internal electron donor compound characterized by the fact that it contains from 0.1 to 50%wt of Bi with respect to the total weight of said solid catalyst component; b) an alkylaluminum compound and, c) an external electron-donor compound selected from: isobutyl triethoxysilane and tetraethoxysilane; step b) propylene and ethylene are polymerized to obtain component B) in the presence of the polymerization product of step A). A) from 50 wt% to 90 wt%; of a propylene homopolymer having a fraction insoluble in xylene at 25 °C, higher than 90 %; and a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 0.5 to 200 g/10 min; B) from 10 wt% to 50wt%; %; of a copolymer of propylene and ethylene having from 30.0 wt% to 70.0wt%, of ethylene derived units; the sum of the amount of component A) and B) being 100; the composition having: i) an intrinsic viscosity of the fraction soluble in xylene at 25 °C comprised between 2.2 and 4.0 dl/g; ii) a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 0.5 to 100 g/10 min; iii) a xylene soluble fraction ranging from 10 wt% to 50 wt%; i) an intrinsic viscosity of the fraction soluble in xylene at 25 °C comprised between 2.2 and 4.0 dl/g; ii) a MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230°C and 2.16 kg load) from 0.5 to 100 g/10 min; iii) a xylene soluble fraction ranging from 10 wt% to 50 wt%; the polypropylene composition being obtained by a two steps polymerization process wherein: step a) propylene is polymerized to obtain component A) in the presence of a catalyst comprising the product of the reaction between: a) a solid catalyst component comprising Ti, Mg, Cl, and an internal electron donor compound characterized by the fact that it contains from 0.1 to 50%wt of Bi with respect to the total weight of said solid catalyst component; b) an alkylaluminum compound and, c) an external electron-donor compound selected from: isobutyl triethoxysilane and tetraethoxysilane; step b) propylene and ethylene are polymerized to obtain component B) in the presence of the polymerization product of step A). step a) propylene is polymerized to obtain component A) in the presence of a catalyst comprising the product of the reaction between: a) a solid catalyst component comprising Ti, Mg, Cl, and an internal electron donor compound characterized by the fact that it contains from 0.1 to 50%wt of Bi with respect to the total weight of said solid catalyst component; b) an alkylaluminum compound and, c) an external electron-donor compound selected from: isobutyl triethoxysilane and tetraethoxysilane; a) a solid catalyst component comprising Ti, Mg, Cl, and an internal electron donor compound characterized by the fact that it contains from 0.1 to 50%wt of Bi with respect to the total weight of said solid catalyst component; b) an alkylaluminum compound and, c) an external electron-donor compound selected from: isobutyl triethoxysilane and tetraethoxysilane; step b) propylene and ethylene are polymerized to obtain component B) in the presence of the polymerization product of step A).