We investigate nonfactorizable contributions to [Formula: see text] and [Formula: see text] decay modes. Obtaining the factorizable contributions from spectator-quark diagrams for N c =3, we determine nonfactorizable isospin amplitudes required to explain the data for these modes. We observe that theoretical ratio of these amplitudes seem to follow a universal value for [Formula: see text] and [Formula: see text] decay modes. We predict the branching ratios for these decay modes.