  We present a systematic study of twist-4 light-cone distribution amplitudes
of the $K^*$ and $\phi$ meson in QCD. The structure of SU(3)-breaking
corrections is studied in detail. Non-perturbative input parameters are
estimated from QCD sum rules and a renormalon based model. As a by-product, we
give a complete reanalysis of the parameters of the twist-4 $\rho$-meson
distribution amplitudes.
