In this paper, which is the third of a series devoted to the title reaction, we present theoretical calculations of branching ratios for the product channels involved in the reaction. In the first paper of this series (Marchand, N.; Jimeno, P.; Rayez, J. C.; Liotard, D. J. Phys. Chem. 1997, 1O1, 6077.), we explored the topology of the lowest triplet potential energy surface determined with sophisticated ab initio methods and proposed several reaction paths connecting the reactants to the products. We have used these results to determine the branching ratios using two methods based on multichannel Rice-Ramsperger-Kassel-Marcus (RRKM) calculations : a mu VTST/RRKM (mu VTST = microcanonical variational transition state theory) method developed by one of us and an ACIOSA/RRKM (ACIOSA = adiabatic capture model using the infinite order sudden approximation) method dealing with a capture rate constant calculation (Marchand, N.; Stoecklin, T.; Rayez, J. C. To be submitted, of this series). Our present results reveal that, at 300 K, HCN + O is the major product channel involved in the reaction (72.0%), the other branching ratios being 13.9% for NCO + H, 8.2% for CO + NH, 3.3% for CNO + H, and 1.4% for CN + OH. All the others channels contribute for less than 1% each. These theoretical results are in agreement with the results of several experimental studies, especially those very recently obtained in our laboratory by Bergeat et al. Moreover, we observe no significant temperature dependence of the branching ratios.