  Consider $\Gamma$, a non-degenerate lattice in $\R^2$ and a constant magnetic
field $B$ with a flux though a cell of $\Gamma$ that is a rational multiple of
$2\pi$. We prove that for a generic $\Gamma$-periodic potential $V$, the
spectrum of the Landau Hamiltonian with magnetic field $B$ and periodic
potential $V$ is purely absolutely continuous.
