  We discuss the phase structure of the NJL model in curved spacetime with
magnetic field using $1/N$-expansion and linear curvature approximation. The
effective potential for composite fields $\bar\psi \psi$ is calculated using
the proper-time cut-off in the following cases: a) at non-zero curvature, b) at
non-zero curvature and non-zero magnetic field, and c) at non-zero curvature
and non-zero covariantly constant gauge field. Chiral symmetry breaking is
studied numerically. We show that the gravitational field may compensate the
effect of the magnetic field what leads to restoration of chiral symmetry.
