Sauber has concluded a deal to use McLaren's Formula 1 gearboxes when it switches to Honda engines in 2018, Autosport understands.
The Swiss outfit announced during the Russian Grand Prix weekend that its association with Ferrari will finish at the end of this season, joining McLaren in being powered by Honda.
In a separate deal, sources have confirmed to Autosport that Sauber will use McLaren's gearboxes, however team principal Monisha Kaltenborn remained tight-lipped.
"I can say nothing on that," Kaltenborn told Autosport.
"Details on the transmission side will not be disclosed right now.
"We'll see in time. No further details at this stage, it is too early, really."
Sauber has sourced its gearboxes as part of a package with Ferrari's power unit in recent years, while they were built at BMW's base in Munich while the team was owned by the German manufacturer between 2006 and '09.
McLaren has previously supplied gearboxes to Force India, while both teams were powered by Mercedes.
The deal indicates McLaren is at least already committed to creating a gearbox that mates with Honda's 2018 engine, even though suggestions it will return to using Mercedes engines linger.