Résumé en anglais

We study a problem involving a set of organizations. Each organization has its own pool of clients who either supply or demand one unit of an indivisible product. Knowing the profit induced by each buyer/seller pair, an organization’s task is to conduct such transactions within its database of clients in order to maximize the amount of the transactions. Inter-organizations transactions are allowed: in this situation, two clients from distinct organizations can trade and their organizations share the induced profit. Since maximizing the overall profit leads to unacceptable situations where an organization can be penalized, we study the problem of maximizing the overall profit such that no organization gets less than it can obtain on its own. Complexity results, an approximation algorithm and a matching inapproximation bound are given.