Formations generated by a group of socle length 2

Gaschütz conjectured that a formation generated by a finite group contains only finitely many subformations. In the present article we prove this conjecture for the groups of socle length at most 2. (We say that a group has socle length 1 if it coincides with its socle and has socle length 2 if its quotient by the socle has socle length 1.) Earlier Gaschütz's conjecture was proven in several particular cases including all soluble groups.