  Starting from known $q$-analogues of ordinary SU(n) tensor products
multiplicities, we introduce $q$-analogues of the fusion coefficients of the
WZW conformal field theories associated with SU(n). We conjecture combinatorial
interpretations of these polynomials, which can be proved in special cases.
This allows us to derive in a simple way various kinds of branching functions,
the simplest ones being the characters of the minimal unitary series of the
Virasoro algebra. We also obtain $q$-analogues of the dimensions of spaces of
nonabelian theta functions.
