  The form factors of the semileptonic $B_c\to S(AV)\ell\nu$ $(\ell=\tau, \mu,
e)$ transitions, where S and AV denote the scalar $X_{c0}$ and axial vector
$(X_{c1}, h_{c})$ mesons, are calculated within the framework of the
three-point QCD sum rules. The heavy quark effective theory limit of the form
factors are also obtained and compared with the values of the original
transition form factors. The results of form factors are used to estimate the
total decay widths and branching ratios of these transitions. A comparison of
our results on branching ratios with the predictions of other approaches is
also presented.
