  We analyse a minimal supersymmetric standard model (MSSM) taking a minimal
flavour violation (MFV) structure at the GUT scale. We evaluate the parameters
at the electroweak scale taking into account the full flavour structure in the
evolution of the renormalization group equations. We concentrate mainly on the
decay Bs -> mu mu and its correlations with other observables like b -> s
gamma, b -> s l l, Delta M_Bs and the anomalous magnetic moment of the muon. We
restrict our analysis to the regions in parameter space consistent with the
dark matter constraints. We find that the BR(Bs -> mu mu) can exceed the
current experimental limit in the regions of parameter space which are allowed
by all other constraints thus providing an additional bound on supersymmetric
parameters. This holds even in the constrained MSSM. Assuming an hypothetical
measurement of BR(Bs -> mu mu) ~ 10^-7 we analyse the predicted MSSM spectrum
and flavour violating decay modes of supersymmetric particles which are found
to be small.
