For both the commercial logistics networks as the non-for-profit ones, collaboration among suppliers is an important strategic resource. This paper considers a tactical model for the optimisation of a commercial supply chain for a non-for-profit relief network, inspired on a previously developed post-disaster logistics model. In order to evaluate the effect of cooperation among the different competitors, a logistic network was simulated and several cooperation scenarios were considered, based on the strengths of each one of the actors involved. The model aims the minimum cost of supplying a specific item for the network and, at the same time, it allows for the different suppliers assess the benefits derived from cooperation. Following a cooperative game theory approach, the Shapley value was calculated in order to determine the distribution of costs as well as the utilities of the players involved and to determine the feasibility of the cooperation scheme designed.