  We construct the fusion ring of a quasi-rational $\hat{sl}(4)_k$ WZNW theory
at generic level $k \not\in Q$. It is generated by commutative elements in the
group ring $Z[\tilde{W}]$ of the affine Weyl group $\tilde{W}$ which extend
polynomially the formal characters of finite dimensional representations of
$sl(4)$.
