  The object of the present study is the integrated density of states of a
quantum particle in multi-dimensional Euclidean space which is characterized by
a Schr{\"o}dinger operator with magnetic field and a random potential which may
be unbounded from above and below. In case that the magnetic field is constant
and the random potential is ergodic and admits a so-called one-parameter
decomposition, we prove the absolute continuity of the integrated density of
states and provide explicit upper bounds on its derivative, the density of
states. This local Lipschitz continuity of the integrated density of states is
derived by establishing a Wegner estimate for finite-volume Schr\"odinger
operators which holds for rather general magnetic fields and different boundary
conditions. Examples of random potentials to which the results apply are
certain alloy-type and Gaussian random potentials. Besides we show a
diamagnetic inequality for Schr\"odinger operators with Neumann boundary
conditions.
