  The process pp -> top anti-top bottom anti-bottom + X represents a very
important background reaction to searches at the LHC, in particular to top
anti-top H production where the Higgs boson decays into a bottom anti-bottom
pair. A successful analysis of top anti-top H at the LHC requires the knowledge
of direct top anti-top bottom anti-bottom production at NLO in QCD. We take the
first step in this direction upon calculating the NLO QCD corrections to the
subprocess initiated by quark anti-quark annihilation.
