Having become the major regional integration scheme today, the EU has made interregional relations into an important pillar of its foreign relations. It supports various regionalist efforts around the globe, not least to receive confirmation and legitimization in the global political arena. However, it would be misleading to assume that the EU follows a common approach towards other regional entities. Based on recent field work, the proposed paper will explore the different nature in the relationships of the EU vis-à-vis SADC and MERCOSUR. It will be argued that the EU follows two different and even independent logics. This can be attributed to structural disparities in the partner organizations and economies as well as to distinct interests of the EU in both regions. Consequently, the EU reveals little interest in fostering tri-regional cooperation or even interregional relations between third partners. The privileging of relations with Europe has in some cases evolved into an unquestioned practice that obstructs relations with third regions. In the course of their extensive and financially important relations with the EU the two regional organisations have mimicked certain institutional structures such as a parliament, a convergence fund or a court. However, these fulfil strikingly different purposes in SADC and MERCSOUR. Supranational structures do not necessarily lead to supranationality or in other words: function does not follow. The EU’s interregionalism has not yielded the expected results in institution building and trade negotiations continue to stall with both regions. As a consequence, the relations have been modified to concentrate on the regional powers Brazil and South Africa and to reshape the region as in the case of the SADC trade negotiations. Hence, interregionalism has to be understood as a flexible concept that is transcending superposing levels of cooperation.
