  The nonleptonic decays
$\Lambda_{b}\rightarrow\Sigma_{c}^{*-}\pi^{+},\Xi_{c}^{*0}K^{0}$ and
$\Lambda_{b}\rightarrow\Delta^{0}D^{0},\Sigma^{*-}D_{0}^{+}$ are studied. In
addition, the decays
$\Lambda_{b}\rightarrow\Xi_{c}^{0}K^{0},\Sigma^{-}D_{s}^{+}$ are analyzed. For
all these decays the dominant contribution comes from $W-$exchange, and for the
decay $\Lambda_{b}\rightarrow\Lambda_{c}^{+}\pi^{-}$, in addition to
factorization, baryon pole contribution to the $p$-wave (parity conserving)
decay amplitude $B$ is discussed.
