The empirical or theoretical question locating it within the scientific literature. This paper will contribute to a better understanding of how multi-stakeholder cooperation dynamics at the territorial scale emerge, develop and, to some extent, are institutionalized. Territorial poles of economic cooperation (PTCEs) are a French type of cluster within the social and solidarity economy that promotes the cooperation between a diversity of stakeholders at the territorial level. Building upon the existing theoretical and empirical works on PTCEs, this paper will address major issues concerning: the purpose of these clusters; the number and degree of heterogeneity of stakeholders; the nature and degree of interactions between them; the governance modes and their mix economic resources. Common findings and lessons from PTCEs may also contribute to underline limits of social enterprise theories in analysing social economic clusters at a meso-level and to build bridges with other fields in the literature, on multi-stakeholder meta-organisations (Berkowitz and al., 2020) and on social clusters in particular. The methodological approach This paper is based on a comparative and secondary analysis of published papers, books, and thesis (see references) on PTCEs in France, including our own work (Fraisse, 2017; Bourbousson, Richez-Battesti, 2017). The main argument of the paper Understanding the recent interest in social economic cluster at the UE level through the French experience of "Territorial poles of economic cooperation" (PTCEs) French "Territorial poles of economic cooperation" (PTCEs) have started to arouse interests from social entrepreneurs, policy makers and researchers at the European level. The role of clusters and similar forms of territorial multi-stakeholder’s cooperation have been recently presented as a tool in fostering the development of social economy. Cooperative clusters are analysed as a way to spread social innovation in order to develop regional change (Gallego-Bono and Chaves, 2019) or to facilitate technology transfer for social entrepreneurship (Guerli and al., 2020). PTCEs appeared at the turn of the 2010s (for a short history, see Fraisse, 2017). They first experienced a rapid process of institutionalization with legal recognition (Article 9 of the SSE Law of 2014) and two inter-ministerial calls for projects in 2013 and 2015. The number is estimated to 56 active PTCEs and 18 inactive (LaboESS 2020). They are defined by the French Law of Social and Solidarity Economy (2014) as “constituted by the grouping on the same territory of companies of the social and solidarity economy, within the meaning of article 1 of this law, which associates with companies, in connection with local authorities and their groupings, research centers, higher education and research institutions, training bodies or any other natural or legal person to implement a common and continuous strategy of sharing, cooperation or partnership in service of innovative economic and social projects, socially or technologically, and sustainable local development” . However, PTCEs are often based on fragile and unstable inter-organizational cooperation dynamics. The cessation of activities, the failure of structuring informal collaborations or the difficulty to build a common narrative in several PTCEs have also to be theoretically and empirically understood. The limits of social enterprise conceptualisation for understanding the dynamic of clustering Social enterprises were relatively absent in the 1990s and 2000s from the literature on industrial districts, local production systems and competitive clusters. The initial definition of social enterprise (Borzaga, Defourny, 2001) identified 9 organisational criteria that differentiate it from others compagnies. The international comparison on social enterprise models (Defourny, Nyssens, 2017) is also focused on organisational principles combining interest (mutual, general and capital interest) and resource mixes of enterprises. Theoretical attempts to articulate social entrepreneurship and social innovation clusters are embryonic (Tanimoto, 2008). If the multi-stakeholder dynamics could characterize certain SE model (Petrella et al. 2021), social enterprise conceptual framework does not provide the theoretical tools for thinking two key aspects of social clusters at a meso-level: the inter-organizational and the territorial dimensions of economic cooperation. Thinking inter-organisational cooperation at the articulation between institutional and organisational levels Empirically, the existing literature on PTCEs highlights the predominance of non-profit organizations, work integration social enterprises and new forms of coops (CAE, SCIC) in the origin as well as in the governance of PTCEs (Fraisse, 2017; Sanossian, 2020). In addition, sustainable local development and social innovation were identified as distinctive purposes of economic territorial cooperation compared to technological transfer and regional integration into globalization often presented as expected impacts of competitive clusters. Theoretically, the literature on PTCE has focused on socio-economic approaches of territorial development (Demoustier et al., 2018), Ostrom’s theory of common resources (Fontaine, 2019), institutional pluralism theory (Bourbousson, 2018) or meta-organization concept (Sanossian, 2020). Beyond this theoretical heterogeneity, our communication highlights common points. In particular, these studies present various types of new institutionalisms either in economic, political or management sciences. They propose to grasp the institutional logics of PTCEs questioning the ability of inter-organizational dynamics, sometimes conceived as collective action, to influence local and regional development in a more cooperative or sustainable perspective.