We present the results of the calculation of QCD corrections to the matching
conditions for the Wilson coefficients of operators mediating the transition
b->s l^+l^- in the context of the MSSM. Within a scenario with decoupled heavy
gluino the calculated contributions together with those present already in the
literature allow for the first time a complete NNLO analysis of B->X_s l^+l^-.
We study the impact of the QCD corrections and the reduction of renormalization
scale dependencies for the dilepton invariant mass distribution and the
forward-backward asymmetry in the inclusive decay B->X_s l^+l^- restricting the
analysis to the "low-s" region and small values of tan(beta). The NNLO
calculation allows to decrease the theoretical uncertainties related to the
renormalization scale dependence below the size of supersymmetric effects in
B->X_s l^+l^- depending on their magnitude. While it will be difficult to
distinguish the MSSM expectations for the branching ratio from the Standard
Model ones, this can become possible in the dilepton invariant mass
distribution depending on the MSSM parameters and \hat{s}. In this respect the
position of the zero of the forward-backward asymmetry s_0 is even more
promising.Comment: 35 pages, 10 figure