  We study mesoscopic fluctuations of the conductance through a quantum dot at
the wings of the Coulomb blokade peaks. At low temperatures, the main mechanism
of conduction is the elastic cotunneling. The conductance strongly fluctuates
with an applied magnetic field. The magnetic correlation field is shown to be
controlled by the charging energy, and the correlation function has a universal
form. The distribution function for the conductance obtained analytically shows
a non-trivial crossover between the orthogonal and unitary ensembles.
