  We investigate spectral correlations in quasi one-dimensional Anderson
insulators with broken time-reversal symmetry. While energy levels are
uncorrelated in the thermodynamic limit of infinite wire-length, some
correlations remain in finite-size Anderson insulators. Asymptotic behaviors of
level-level correlations in these systems are known in the large- and
small-frequency limits, corresponding to the regime of classical diffusive
dynamics and the deep quantum regime of strong Anderson localization. Employing
non-perturbative methods and a mapping to the Coulomb-scattering problem,
recently introduced by {\it M.~A.~Skvortsov} and {\it P.~M.~Ostrovsky}, we
derive a closed analytical expression for the spectral statistics in the
classical-to-quantum region bridging the known asymptotic behaviors. We further
discuss how Poisson statistics at large energies develop into Wigner-Dyson
statistics as the wire-length decreases.
