Résumé : In this paper, we propose a multi-agent framework to distributively solve this kind of assignment problems, by providing agents representing users and negotiating with respect to their preferences. The objective of such procedure is to find an assignment that is optimal. For this purpose, we can consider different notions of social welfare. For instance, the aim of the utilitarian social welfare is to maximise the sum of individual utilities. Within this paper, we propose Casanova, a distributed method to solve the stable marriage problem. We seek to provide agent behaviors leading negotiation processes to socially optimal assignments. We propose a realisation of the minimal concession strategy applied to the stable marriage problem. According to this strategy, agents start the negotiation with their preferred partners. During the negotiation, an agent concedes minimally as soon as its optimal partners has refused. Our strategy has useful properties. Firstly, it preserves the privacy since the agents do not reveal explicitly their preferences. Secondly, the approach improves the optimality of the solution and the equity amongst partners (e.g. men and women).