  A brief summary of the recent next-to-leading order QCD calculation for e+ ve
mu- v_mu bb~ j at the LHC is given. Our computation includes all non-resonant
contributions, off-shell effects and interferences for top-quarks and W gauge
bosons. Some results for integrated and differential cross sections are shown
for the LHC Run1 energy of 8 TeV. A significant reduction of the scale
dependence is observed, which indicates that the perturbative expansion is well
under control. The results are obtained in the framework of the HELAC-NLO
system.
