  We present a measurement of asymmetries in the production of $\Lambda_c^+$
and $\Lambda_c^-$ baryons in 500 GeV/c $\pi^-$--nucleon interactions from the
E791 experiment at Fermilab. The asymmetries were measured as functions of
Feynman x ($x_F$) and transverse momentum squared ($p_T^2$) using a sample of
$1819 \pm 62$ $\Lambda_c$'s observed in the decay channel $\Lambda_c \to
pK^-\pi^+$. We observe more $\Lambda_c^+$ than $\Lambda_c^-$ baryons, with an
asymmetry of $(12.7\pm3.4\pm1.3) %$ independent of $x_F$ and $p_T^2$ in our
kinematical range $(-0.1 < x_F < 0.6$ and $0.0 < p_T^2 < 8.0 (GeV/c)^2$). This
$\Lambda_c$ asymmetry measurement is the first with data in both the positive
and negative $x_F$ regions.
