  We present a systematic study of twist three light-cone distribution
amplitudes of vector mesons in QCD, which is based on conformal expansion and
takes into account meson and quark mass corrections. A complete set of
distribution amplitudes is constructed for rho, omega, K* and phi mesons, which
satisfies all (exact) equations of motion and constraints from conformal
expansion. Nonperturbative input parameters are calculated from QCD sum rules,
including an update of SU(3) breaking corrections in the leading twist
distributions.
