  The atmospheric neutrino flux calculated with FLUKA was originally limited to
100-200 GeV for statistical reasons. In order to make it available for the
analysis of high energy events, like upward through-going muons detected by
neutrino telescopes, we have extended the calculation so to provide a reliable
neutrino yield per primary nucleon up to about 10**6 GeV/nucleon, as far as the
interaction model is concerned. We point out that the primary flux model above
100 GeV/nucleon still contributes with an important systematic error to the
neutrino flux.
