  We derive the S parameter of the electroweak radiative corrections in a
scaled-QCD technicolour and using a Nambu-Jona Lasinio model for hadronic low
energy interactions. In this framework deviations from low energy QCD can be
quantitatively deduced. We induce explicit chiral symmetry breaking in the NJL
model through the current-quarks mass term. It is shown that the prediction for
the S parameter can be sensitively reduced respect to the chiral prediction.
