  The reactive collisions of the CH$^+$ molecular ion with electrons is studied
in the framework of the multichannel quantum defect theory, taking into account
the contribution of the core-excited Rydberg states. In addition to the
$X^1\Sigma^+$ ground state of the ion, we also consider the contribution to the
dynamics of the $a^3\Pi$ and $A^1\Pi$ excited states of CH$^+$. Our results -
in the case of the dissociative recombination in good agreement with the
storage ring measurements - rely on decisive improvements - complete account of
the ionisation channels and accurate evaluation of the reaction matrix - of a
previously used model.
