Agricultural cooperatives have an original organizational structure in which their democratic governance is directed towards the community in every sense. In this context, we have examined to what extent a stronger partnership with external actors would create value for the cooperatives. We surveyed a representative sample of winemaking cooperatives in Languedoc-Roussillon and analyzed their partnership governance methods, their size, their performance and the effects of the first two points on the third one using structural equation modelling. It was found that frequent and extensive interaction between the winemaking cooperatives and their external stakeholders was a source of additional performance in the long term, an effect which is added to that of the size.