Mercedes F1 boss Norbert Haug has confirmed the company split from McLaren because of its desire to build the MP4-12C supercar.
Mercedes set up its own F1 team after buying the championship-winning Brawn squad last winter, and is gradually selling back its shareholding in McLaren. It will, however, supply F1 engines to McLaren until at least 2015.
The McLaren MP4-12C supercar is set to go on sale next year, and Haug says this was the reason behind the split.
"McLaren wanted to go in their own direction with their street sports car," he said. "At Mercedes we have been doing it for many years. It (McLaren's) was not our way and we found an amicable solution.
"We continue to supply them with engines but we have created our own team. We are grateful about our many joint successes. Only Ferrari was more successful than us."