An algorithm for the combined retrieval of ozone, NO₂, spectral aerosol extinction profiles and different microphysical properties of stratospheric aerosol is described. Principal features of the algorithm are the use of simulated statistical aerosol models as a priori information and optimal parameterization of spectral dependence of aerosol extinction coefficients (by expanding in natural orthogonal basis). The statistical microphysical models of stratospheric aerosols are used for retrieving the aerosol size distribution function. Results of numerical experiments for the study of error budget of this algorithm are given. Data of slant path transmittance spectral measurements by SAGE III (Meteor-3M) have been processed and analyzed. Results of retrieving the different atmospheric parameters are compared with independent measurements.