Reigning MotoGP world champion Jorge Lorenzo will join Ducati following the 2016 season.
The 28-year-old Spaniard has won three World Championship titles during an eight-year spell with Movistar Yamaha, clinching 41 wins in 141 races.
Yamaha, who gave Valentino Rossi a two-year extension in March, said Lorenzo has the "team's full support in his campaign to achieve a fourth title".
Lorenzo has signed a deal with Ducati for the 2017 and 2018 seasons.
Yamaha added: "Yamaha is extremely grateful for Jorge's contributions to its racing successes and looks forward to sharing more memorable moments during the remaining 15 MotoGP rounds of 2016."
Lorenzo claimed victory in the opening MotoGP of the campaign in Qatar, but Honda's Marc Marquez has won the two races since.