  Recent experimental studies of magneto-resistance in disordered
superconducting thin films reveal a huge peak (about 5 orders of magnitude).
While it may be expected that magnetic field destroys superconductivity,
leading to an enhanced resistance, attenuation of the resistance at higher
magnetic fields is surprising.
  We propose a model which accounts for the experimental results in the entire
range of magnetic fields, based on the formation of superconducting islands due
to fluctuations in the superconducting order parameter amplitude. At strong
magnetic fields Coulomb blockade in these islands gives rise to negative
magneto-resistance. As the magnetic field is reduced the effect of Coulomb
blockade diminishes and eventually the magneto-resistance changes sign.
Numerical calculations show good qualitative agreement with experimental data.
