  We consider the influence of a magnetic field H on the quasiparticle bound
states near scalar impurities in d-wave superconductors. A ``Doppler shift'' in
the excitation energies induced by the supercurrent leads to several important
effects. At large but finite impurity strength, there are corrections to the
energy and width of the impurity-induced resonance, proportional to H^2. On the
other hand, in the limit of very strong impurity potential (unitary limit), the
bound state is destroyed and acquires a finite width proportional to H/ln H.
There are also considerable changes in the asymptotic behaviour of the bound
state wave functions.
