  We study models of gauge-mediated supersymmetry breaking with a gauged
horizontal SU(3)_F symmetry acting on the quark superfields. If SU(3)_F is
broken non-supersymmetrically by F-term vacuum expectation values, the massive
gauge bosons and gauginos become messengers for SUSY breaking mediation. These
gauge messenger fields induce a flavour-dependent, negative contribution to the
soft masses of the squarks at one loop. In combination with the soft terms from
standard gauge mediation, one obtains large and degenerate first- and
second-generation squark masses, while the stops and sbottoms are light. We
discuss the implications of this mechanism for the superparticle spectrum and
for flavour precision observables. We also provide an explicit realization in a
model with simultaneous SUSY and SU(3)_F breaking.
