  We calculate the contribution to the spin transfer torque from sequential
tunneling through impurities in a magnetic tunnel junction. For a junction with
weakly polarized ferromagnetic contacts, the torque is found to be in the plane
spanned by the magnetizations of the ferromagnetic contacts and proportional to
$\sin \theta$, where $\theta$ is the angle between the magnetic moments. If the
polarization is larger, the torque acquires a significant out-of-plane
component and a different dependence on $\theta$.
