  When the strong CP problem is solved by spontaneous breaking of an anomalous
global symmetry in theories with gauge-mediated supersymmetry breaking, the
pseudo Goldstone fermion (the axino) is a good candidate of a light sterile
neutrino. Its mixing with neutrinos relevant for current neutrino experiments
can arise in the presence of R-parity violation. The realistic four neutrino
mass matrix is obtained when the see-saw mechanism is brought in, and an ansatz
for the right-handed neutrino mass is constructed.
