  It is shown theoretically that a giant magnetoelectric susceptibility
exceeding 10^-6 s/m may be achieved in the ferromagnetic/ferroelectric
epitaxial systems via the magnetization rotation induced by an electric field
applied to the substrate. The predicted magnetoelectric anomaly results from
the strain-driven spin-reorientation transitions in ferromagnetic films, which
take place at experimentally accessible misfit strains in CoFe2O4 and Ni films.
