This paper studies the magnetoelectricity of a core-shell-matrix three-phase particulate composite made of piezoelectric (PE) and piezomagnetic (PM) phases. We propose a micromechanical model, the two-level recursive scheme in conjunction with Mori-Tanaka's method, to investigate the effective magnetoelectric coupling coefficients of the composite. We compare this micromechanical solution with those predicted by finite element analysis, which provides the benchmark results for a periodic array of inclusions. Both the magnitudes and trends between them are in good agreement. Based on this micromechanical approach, we show that, for the case of PE/PM/PM (core/shell/matrix) multiferroic composite, with a coating appropriate for the inhomogeneity, the effective magnetoelectric coupling can be enhanced many-fold as compared to the noncoated counterpart. Further, useful design principles are proposed for engineering magnetoelectric composites.