  We study fractional exclusion statistics for quantum systems with SU(2)
symmetry (arbitrary spin $S$), by generalizing the thermodynamic equations with
squeezed strings proposed by Ha and Haldane. The bare hole distributions as
well as the statistical interaction defined by an infinite-dimensional matrix
specify the universality class. It is shown that the system is described by the
level-$2S$ WZW model and has a close relationship to non-abelian fractional
quantum Hall states. As a low-energy effective theory, the sector of {\it
massless} Z$_{2S}$ parafermions is extracted, whose statistical interaction is
given by a finite-dimensional matrix.
