  We summarize a recent calculation of the evolution kernels of the
two-particle B-meson distribution amplitudes $\phi_+$ and $\phi_-$ taking into
account three-particle contributions. In addition to a few phenomenological
comments, we give as a new result the evolution kernel of the combination of
three-particle distribution amplitudes $\Psi_A-\Psi_V$ and confirm constraints
on $\phi_+$ and $\phi_-$ derived from the light-quark equation of motion.
