  We study two-dimensional interacting electrons in a weak perpendicular
magnetic field with the filling factor $\nu \gg 1$ and in the presence of a
quenched disorder. As it is known, the unidirectional charge density wave state
can exist near a half-filled high Landau level at low temperatures if disorder
is weak enough. We show that the existence of the unidirectional charge density
wave state at temperature $T<T_c$ where $T_c$ is the transition temperature
leads to the anisotropic conductivity tensor. We find that the anisotropic part
of conductivity tensor is proportional to $(T_c-T)/T_c$ below the transition in
accordance with the experimental findings. The order parameter fluctuations
wash out the mean-field cusp at $T=T_c$ and the conductivity tensor becomes
anisotropic even above the mean-field transition temperature $T_c$.
