On Ideals in Group Algebras of [FIA]B-Groups. In this paper we consider closed B-invariant ideals in the group algebra LI(G), where G is a locally compact group with a relatively compact group B of topological automorphisms, which contains the set of all inner automorphisms. We study conditions when closed B-invariant ideals are completely determined by their hull. Also questions concerning the existence of approximate units in these ideals will be answered. Above all, we shall study these properties with regard to the relations between ideals in LI(G), LI(G/N) and LI(N), where N is a closed Bdnvariant subgroup of G.