  The calculation of NLO QCD corrections to the $t\bar{t}\to
W^{+}W^{-}b\bar{b}\to e^{+}\nu_e \mu^{-}\bar{\nu}_{\mu}b\bar{b}$ process with
complete off-shell effects, is briefly summarized. Besides the total cross
section and its scale dependence, a few differential distributions at the
TeVatron run II and LHC are given. All results presented in this contribution
have been obtained with the help of the HELAC-NLO Monte Carlo framework.
