Mercedes and BMW also work together in the development of Hybrid technology, however this report is from just over a week ago:
Mercedes: we don’t want to work with BMW Maier, who was interviewed by Handelsblatt, acknowledged that the two had worked together in the past, commenting “we cooperate naturally with BMW in a few technical areas, like development of hybrid engines.” However, the consensus in the Mercedes boardroom is that there are no plans to work together beyond the current co-development of hybrid drivetrains.