The branching bisimulation de ned by Van Glabbeek and Weijland takes care of preserving the branching structure of processes even though silent actions are taken. Branching bisimulation is obviously decidable for nite state processes. A proof that it is also decidable for reduced and proper context-free processes has been given by Huttel. Going further along these lines, we prove that the class of reduced and proper context-free processes is closed under quotient by their greatest branching bisimulation. Moreover, the construction of the factor graph is in pspace.