A period of intense debate (at least in Europe) on competition law and sustainability has yielded helpful agency guidance. There is now a transition to concrete action – in terms of actual competitor collaboration (being waved through by agencies), but also high-profile enforcement against agreements to restrict technical development at the expense of the environment. Agencies are also debating whether and how to address sustainability-related factors in their merger control analysis. Our panel will discuss the journey so far and the road ahead: what are the key areas of convergence and divergence? What teachings can be drawn from the cases that have come to light so far involving cooperation?