Renault have announced that Carlos Sainz is to join the team on loan from Red Bull in 2018, taking over from British driver Jolyon Palmer.
The 23-year-old had been expected to stay at Toro Rosso, where he has spent the last three years, but he will link up with Nico Hulkenberg in time for next season.
Sainz's current team had earlier revealed their intention to switch to Honda engines for the next three seasons while, in a separate announcement, Renault outlined a new engine supplier partnership with McLaren.
In a statement issued on Friday, Renault Sport managing director Cyril Abiteboul said: "Carlos Sainz is a very promising driver who has been on our radar for some time. We feel Nico and Carlos will complement each other on and off track and help us push forwards on the grid."
Sainz added: "To be a Formula 1 driver for a manufacturer team is an honour, and I hope to reward Renault's faith in me with my very best performances on track. The trajectory of Renault Sport F1 team is exciting and I'm proud to join at such an important time in their history."
As part of the arrangement, Red Bull can bring back Sainz to their senior team for 2019 should they wish.