  Long-time asymptotic of field-field correlator for radiation propagated
through a medium composed of random point-like scatterers is studied using
Bete-Salpeter equation. It is shown that for plane source the fluctuation
intensity (zero spatial moment of the correlator) obeys a power-logarithmic
stretched exponential decay law, the exponent and preexponent being dependent
on the scattering angle. Spatial center of gravity and dispersion of the
correlator (normalized first and second spatial moments, respectively) prove to
weakly diverge as time tends to infinity. A spin analogy of this problem is
discussed.
