Finite Groups in Which Sylow Normalizers Admit Supplements

For a group G and a subgroup M of G, we say that a subgroup A of G is a supplement to M in G, if G = MA. We prove that a finite group in which every Sylow normalizer admits a nilpotent supplement is solvable. In particular we confirm a conjecture of Buchthal. Moreover we investigate finite groups in which Sylow normalizers admit solvable supplements.