This PhD thesis work addresses the following problem: can Cross-Sector Social Partnerships (CSSP) be a strategic lever for the implementation of Corporate Social Responsibility? Going beyond the phenomenon of collaboration between the company and the nonprofit organization, this research helps legitimize the role of a little known stakeholder, civil society. This work relied upon action research methodology. In cooperation with researchers, action research aims to create knowledge for and with practitioners. The CCSPs are presented from two different perspectives as one action research was developed in Grenoble, France, and the other was made in New York City, United States. The first analysis explains the phenomenon from the perspective of the company and the second shows the view of the non-profit organization. To understand the CSSP process, the eleven societal partnerships studied are broken down into four phases: 1) initialization and definition of strategy; 2) selecting the right partner; 3) recurrent dynamics; and 4) relational interdependence. The purpose of this phenomenon is the social and/or environmental value creation; economic interest is complementary and not a priority. Exceeding their respective organizational goals, the collaborative project's stakeholders work together to find a solution to a common problem. This process of CSSP embodies corporate social responsibility. The phase of trial and error between deliberate strategy and emergent strategy tends to increase as part of a CSR strategy. Civil society acts as an interface between citizens and the business. As a member of a local area network, civil society provides access to new resources and skills. The company benefits from its association with social and environmental nonprofits organizations, while the nonprofit organization hope the company provides financial resources. However, the organizational culture of a company and an association differ. To work together, stakeholders of the project have to go beyond their own interests to exceed their respective organizational goals. However, during the collaborative process, the company tends to impose its will on the partnership. Finally, the maturity of the project is perceived by a collective sense of belonging to the same team. The purpose of the process is to provide value creation for stakeholders, but for society as a whole it may be varied.
