Red Bull junior team Toro Rosso will switch to Ferrari engines from Renault next season.
The long-expected move comes on the day senior team Red Bull announced they would continue with Renault.
Toro Rosso are to use 2015-spec Ferrari engines, while the factory Ferrari team and customers Sauber and Haas will use the new 2016 design.
Toro Rosso will continue with drivers Max Verstappen and Carlos Sainz Jr, who impressed in their debut seasons.
The drivers' positions were not announced by the team along with the engine deal on Friday but were confirmed by Red Bull motorsport adviser Helmut Marko in an interview with the drinks giant's Speedweek website.
Identical joint statements from Toro Rosso and Ferrari were not completely clear on the specification of the engine the team would use, referring only to the "current Ferrari power-unit".
However, a Toro Rosso spokeswoman confirmed that the team would be using the specification of engine that Ferrari used at the end of this season.
The deal raises the intriguing possibility of the junior Red Bull team out-pacing the senior outfit.
That's because the Ferrari engine was this year significantly more powerful than the Renault and the Toro Rosso car was not far off the Red Bull in terms of chassis performance.
Renault has found it difficult to make progress with the performance of its engine since the introduction of the turbo hybrid formula in 2014 - a development version of the engine introduced at the penultimate race of the season in Brazil proved to have less power than the previous version.
However, Marko has expressed confidence in the developments planned by Renault, who will be assisted by British engineering company Ilmor.
"The concepts presented by Renault look good," Marko said. "Now they need to be implemented and respected in practice what they promise in theory. The question is how quickly that will be possible."