  We discuss a specific model of extended GMSB type in which 5bar component of
one messenger vector pair is treated as an extra flavour. FCNC effects related
to the superpotential couplings between 5bar messenger and i-th family of MSSM
matter, h_i, are analysed. We find that the strongest limit, h_1h_2<10^{-3},
emerges from constraints on RR slepton contribution to radiative muon decay.
The results are in agreement with simple models of hierarchical Yukawa
interactions.
