  Using large N_f methods we compute the anomalous dimension of the
predominantly gluonic flavour singlet twist-2 composite operator which arises
in the operator product expansion used in deep inelastic scattering. We obtain
a d-dimensional expression for it which depends on the operator moment n. Its
expansion in powers of epsilon = (4-d)/2 agrees with the explicit exact three
loop MSbar results available for n less than or equal to 8 and allows us to
determine some new information on the explicit n-dependence of the three and
higher order coefficients. In particular the n-dependence of the three loop
anomalous dimension gamma_{gg}(a) is determined in the C_2(G) sector at
O(1/N_f).
