  The fit of the experimental data on c-axis magnetoresistance of HTS above the
transition temperature with the theory based on the fluctuation renormalization
of the one-electron density of states (DOS) is exellent in weak magnetic fields
but meets the noticible difficulties in the region of strong fields. This is
due to the formal divergency of the DOS contribution to conductivity and the
dependence of the cut-off parameter on the magnetic field itself. We propose
the scheme of the regularization of the problem. This permits us to obtain the
expression for the magnetic field dependent part of DOS conductivity as a
convergent serie independent on cut-off. We also calculate analitically the
asymptotics for all regions of magnetic fields. The results demonstrate the
robustness of the DOS contribution with respect to the magnetic field effect:
in strong fields it decreases logarithmically only while Aslamazov-Larkin and
anomalous Maki-Thompson contributions diminish as powers of H_{c2}/H.
