The present invention concerns a process for producing a polymer blend comprising a first phase containing a polyacrylate polymer prepared by radical polymerization and a source of radicals, and a second phase containing a polyolefin polymer. According to the invention, the blend is compounded by melt processing and the termination reactions of free radicals derived from the source of radicals are preferably retarded by introducing N,N'-m-phenylene-dimaleimide or a similar peroxide accelerator into the blend before melt blending thereof. The introduction of a peroxide accelerator will promote formation of cross-links in the polyacrylate phase and thus improve the elastomeric properties of the blend.