A process for preparing polyolefin blends comprising:a) polymerizing in a solution phase propylene or 1-butene to prepare a polymeric solution containing a semicrystalline polymer component;b) polymerizing in a solution phase 1-hexene or 1-octene to prepare a polymeric solution containing an amorphous polymer component;c) mixing the polymeric solutions obtained from steps a) and b);d) subjecting the mixture of step c) to a devolatilization step to separate a polyolefin blend comprising a semicrystalline component and an amorphous component;the polymerization steps a) and b) being carried out in two polymerization reactors connected in parallel.