2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70623We prove that SU(n) (n > 2) and Sp(n)U(1) (n > 1) are the only connected Lie groups acting transitively and effectively on some sphere which can be weak holonomy groups of a Riemannian manifold without having to contain its holonomy group. In both cases the manifold is Kaehler.17 pages, LATEX; two references addedDifferential Geometry53C29text