MotoGP rider Makoto Tamada will compete for the Yamaha Tech3 team in 2007.
Tamada had been told he could leave Minolta at the end of the season
The 29-year-old from Japan, who made his debut in 2003 and won two races in 2004, moves from Konica Minolta Honda.
"He is an excellent rider who has proved himself many times on the podium and by winning two Grand Prix," said Tech3 team chief Herve Poncharal.
Carlos Checa leaves Tech3 to ride for Honda LCR next year. Konica Minolta Honda have replaced Tamada with another Japanese rider, Shinya Nakano.
The 29-year-old spent the last three seasons with Kawasaki.
The future of Britain's James Ellison remains unclear after a disappointing season with Yamaha.