Twelve years after it first supplied Red Bull with engines, Renault believes the time will be right to split with the championship-winning Formula One team at the end of the year.
Red Bull has signed a new two-year contract with Honda from 2019 that will bring an end to a successful but uneasy relationship with Renault, which accounts for all four of the team's titles and 57 grands prix victories but has also come under strain in recent years.
Renault's struggle to match the power outputs of class leaders Mercedes and Ferrari since the start of the turbo-hybrid era in 2014 has led to very public disputes with Red Bull over the performance of its engine in recent seasons. What's more, Renault returned to F1 as a full works team in 2016 and, despite using Red Bull as a benchmark to measure its chassis performance against, is now focusing on its own title challenge by 2020.
"Two years after Renault's return as a works team, we consider this is a natural evolution for both Renault and Red Bull Racing in view of their respective aspirations," a team statement said.
"In an extremely demanding and competitive environment we are proud of the extraordinary results achieved with Red Bull Racing over the past 12 seasons, in particular, the four Drivers' and Constructors' World Championships and 57 wins we have taken together. After two seasons, we are fully focused on the strong progression of Renault Sport Formula One Team, while continuing to foster the fresh relationship with McLaren Racing."
Red Bull team principal Christian Horner added: "We would like to thank Renault for the past 12 years, a period during which we experienced some incredible moments together. We have sometimes had our differences but Renault has always worked tirelessly and to the best of its ability to provide us with a competitive power unit.
"That is still the case today and we would like to thank the Renault team, and particularly the guys in our garage at every race, for their unstinting commitment and we look forward to ending our partnership on a high come the end of this season. Our focus for the rest of this year is still very much on delivering the best results possible in the 2018 championship and we wish Renault Sport all the best for the future."