[en] Deviations from the QCD prediction for the three-gluon vertex can be parameterised in terms of the dimension-6 operator Tr(G_μ^νG_ν^ρG_ρ^μ) in a guage invariant way. Tree level unitarity considerations for the gg→gg elastic scattering process severely constrain the signal for an anomalous three-gluon vertex in dijet production at hadron colliders. This leaves four-jet events at e⁺e^- colliders as a very competitive way to study the three-gluon vertex. (orig.)