The potential failure of national industry agreements to take into account productivity levels of least productive regions has been considered as one of the causes of regional unemployment in European countries. Two solutions are generally proposed: the first, encouraged by the European commission and the OECD, consists in decentralising wage bargaining to the firm. The second solution, the regionalisation of wage bargaining, is frequently mentioned in Belgium or in Italy where regional unemployment differentials are high. The objective of this paper is to verify if the Belgian wage setting system, where industry bargaining has a national scope, indeed prevents regional productivity levels to be taken into account in wage formation. Using a very rich linked employer-employee dataset which provides detailed information on wages, productivity, and worker's and firm's characteristics, we find that regional wage differentials and regional productivity differentials within joint committees are positively correlated. Moreover, this relation is stronger (i) for joint committees where firm-level bargaining is relatively frequent and (ii) for joint committees already sub-divided along a local line. We conclude that the current Belgian wage setting system (which combines interprofessional, industry and firm level bargaining) already includes mechanisms that allow regional productivity to be taken into account.