Japanese driver Takuma Sato has been unveiled as BAR's replacement for former world champion Jacques Villeneuve for the 2004 Formula One season.
"There comes a time in all relationships where you have to move on," BAR managing director Dave Richards told a news conference on Tuesday.
"Some people think it was a pre-determined decision taken a long time ago but I can contradict that completely. It came after long debate and the decision was taken internally."
The 26-year-old Sato raced for Jordan last season but returned to BAR as a test driver for 2003.
Villeneuve will drive in his last race for BAR at the season-ending Japanese Grand Prix in Suzuka on Sunday.
