  We compute the order alpha_s^3 (next-to-leading) corrections to the Wilson
coefficients of the Delta F=2 effective Hamiltonian in the Minimal
Supersymmetric Standard Model with completely arbitrary soft terms. These
results are relevant for phenomenological studies of neutral meson mixings in
the presence of large squark mass splittings, in particular in hierarchical
scenarios of supersymmetry. These corrections achieve a considerable reduction
of the uncertainty related to the matching scale ambiguity, and are therefore
numerically relevant. We briefly analyze the effect of certain mass splittings
on the size of the NLO corrections, and compare it with the case of almost
degenerate squarks in the mass insertion approximation.
