Abstract: Polyolefin compositions, comprising (percent by weight): 1) 55-80% of a homopolymer or copolymer of propylene, said copolymer containing up to 15% of ethylene and/or C4-C10 ?-olefin(s). 2) 20-45% of a copolymer of ethylene with one or more C4-C10 ?-olefin(s) containing from 10 to 40% of said C4-C10 ?-olefin(s); said compositions having values of MFR (230° C., 2.16 kg) up to 20 g/10 min, a total content of ethylene of 20% or more, a total content of C4-C10 ?-olefin(s) of 4.5% or more, a ratio of the total content of ethylene to the total content of C4-C10 ?-olefin(s) of 2.3 or more, a total fraction soluble in xylene at room temperature of 18 wt % or higher and flexural modulus, referred to the composition as a reactor grade, of more than 700 MPa.