  We study the conductance (g) distribution function of an ensemble of isolated
conducting rings, with an Aharonov--Bohm flux. This is done in the discrete
spectrum limit, i.e., when the inelastic rate, frequency and temperature are
all smaller than the mean level spacing. Over a wide range of g the
distribution function exhibits universal behavior P(g)\sim g^{-(4+\beta)/3},
where \beta=1 (2) for systems with (without) a time reversal symmetry. The
nonuniversal large g tail of this distribution determines the values of high
moments.
