Ito's theorem and metabelian Leibniz algebras

We prove that the celebrated Ito's theorem for groups remains valid at the level of Leibniz algebras: if g is a Leibniz algebra such that g = A + B, for two abelian subalgebras A and B, then g is metabelian, i.e. [[g, g], [g, g]] = 0. A structure-type theorem for metabelian Leibniz/Lie algebras is proved. All metabelian Leibniz algebras having the derived algebra of dimension 1 are described, classified and their automorphisms groups are explicitly determined as subgroups of a semidirect product of groups P* (sic) (k* x Aut(k) (P)) associated to any vector space P.