This study seeks to provide insights into the management of coopetitive tensions at the working‐group level. We theoretically discuss the principles of separation and integration and a combination of both to manage coopetitive tensions at this level. An in‐depth case study of a space programme conducted by two competitors − Astrium and Thales Alenia Space − was conducted. At the organizational level, according to the separation principle, we found that the coopetitors implemented a Coopetitive Project Team separated from the rest of their organization. At the individual level, according to the integration principle, we evidenced that project managers internalize the coopetitive paradox. At the working‐group level, we revealed a new principle, that of co‐management. The co‐management principle, in the case of dyadic coopetition, relies on the implementation of a dual, equally shared governance structure and a dual management committee. To efficiently manage coopetitive tensions, firms are combining the separation principle at the organizational level, the co‐management principle at the working‐group level and the integration principle at the individual level.