Using recent experimental data on photoelectron spin polarisation combined with the high-resolution spectrum of methyl bromide, which has also been recently reported, the partial photoionisation cross sections for the ionisation of CH3Br from the 4 pi ground-state orbital into the energy degenerate continua epsilon sigma , epsilon pi and epsilon delta have been determined separately. Quantitative results, obtained for the autoionising resonances between 116 and 118 nm, are reported and discussed.