  We present results for different observables measured in semileptonic and
non-leptonic decays of the $B_c^-$ meson. The calculations have been done
within the framework of a nonrelativistic constituent quark model. In order to
check the sensitivity of all our results against the inter-quark interaction we
use five different quark--quark potentials. We obtain form factors, decay
widths and asymmetry parameters for semileptonic $B_c^-\to c\bar c$ and
$B_c^-\to \bar B$ decays. In the limit of infinite heavy quark mass our model
reproduces the constraints of heavy quark spin symmetry. For the actual heavy
quark masses we find nonetheless large corrections to that limiting situation
for some form factors. We also analyze exclusive non-leptonic two--meson decay
channels within the factorization approximation.
