  Recent data for B decays to two light vector mesons show that the
longitudinal amplitude dominates in $B^0 \to \rho^+ \rho^-$, $B^+ \to \rho^+
\rho^0$, $\rho^0 K^{*+}$ decays and not in $B^0 \to \phi K^{*0}$, $B^+ \to \phi
K^{*+}$. We consider rescattering mediated by charmed resonances, finding that
in $B \to \phi K^*$ it can be responsible of the suppression of the
longitudinal amplitude. A similar result is found for $B \to \rho K^{*}$.
