  A new method of path averaging for waves propagating in a random dilute
system of identical scatterers is developed. The scattering matrix of such a
system is calculated. The method systematically takes into account repeating
scatterings on the same scatterer and effects of correlations. Results obtained
show the significant influence of new effects on the extinction of a coherent
field and are valid in both the diffusive and localized regimes.

Condensed Matter