  We study the Schroedinger operator with a constant magnetic field in the
exterior of a two-dimensional compact domain. Functions in the domain of the
operator are subject to a boundary condition of the third type (Robin
condition). In addition to the Landau levels, we obtain that the spectrum of
this operator consists of clusters of eigenvalues around the Landau levels and
that they do accumulate to the Landau levels from below. We give a precise
asymptotic formula for the rate of accumulation of eigenvalues in these
clusters, which appears to be independent from the boundary condition.
