  We study the anomalous dimensions of single trace operators composed of field
strengths $F_{\mu\nu}$ in large-N QCD. The matrix of anomalous dimensions is
the Hamiltonian of a compact spin chain with two spin one representations at
each vertex corresponding to the selfdual and anti-selfdual components of
$F_{\mu\nu}$. Due to the special form of the interaction it is possible to
study separately renormalization of purely selfdual components. In this sector
the Hamiltonian is integrable and can be exactly solved by Bethe ansatz. Its
continuum limit is described by the level two SU(2) WZW model.
