  The recent developments on the computation of non-resonant corrections to the
e+ e- -> W+ W- b bbar cross section in the top-antitop resonance region are
reviewed in this talk. Non-resonant production of the final state W+ W- b bbar
starts to contribute at NLO in the nonrelativistic power-counting v ~ alpha_s ~
sqrt(alpha_EW). The corrections induced by non-resonant effects reduce the
cross section in the top-antitop resonance peak region at a level which is
comparable to the expected experimental precision at the future linear
collider, and are thus relevant for a high-precision top mass and width
determination.

High Energy Physics - Phenomenology