  We analyze the asymmetry in the partial widths for the decays $B^{\pm} \to M
{\bar M} \pi^{\pm}$ ($ M = \pi^+, K ^+, \pi^0, \eta$), which results from the
interference of the nonresonant decay amplitude with the resonant amplitude for
$B^{\pm} \to \chi_{c0} \pi^{\pm} $ followed by the decay $\chi_{c0} \to M {\bar
M} $. The CP violating phase $\gamma$ can be extracted from the measured
asymmetry. We find that the partial width asymmetry for $B^\pm \to \pi^+ \pi^-
\pi^\pm$ is about $0.33~sin \gamma$, and about $0.45~ sin \gamma$ for $B^\pm
\to K^+ K^-\pi^\pm$, while it is somewhat smaller for $B^\pm \to \pi^0 \pi^0
\pi^\pm$ and $B^\pm \to \eta \eta \pi^\pm$. Potential sources of uncertainties
in these results, primarily coming from poorly known input parameters, are
discussed.
