Abstract:
We prove the following result: Let$\mathcal{F}$be a hereditary saturated formation of$p$-soluble groups containing all$p$-supersoluble
groups such that$\mathcal{F}=\mathcal{G}_p\mathcal{F}$. Let$G=AT$where$A$is a Hall$\pi$-subgroup of$G$, $p\notin\pi$ and $T$is a$p$-supersoluble subgroup of$G$. Suppose that for a Sylow$p$-subgroup $P$of$T$we have$|P|>p$. If$A$permutes with a Hall$p'$-subgroup of$T$and with all
maximal subgroups$V$of$P$such that$G^{\mathcal{F}}\cap P\not\leqslant V$, then$G\in\mathcal{F}$.
Keywords:finite group, saturated formation, $p$-soluble group, $p$-supersoluble group, Hall subgroup.