Jenson Button has told BAR principal Dave Richards he will not go back on his decision to join Williams next season.
The British driver announced on Thursday he would be leaving BAR at the end of the season after agreeing a two-year deal with Williams.
BAR however threatened legal action to block the move, claiming they had a binding contract with the 24-year-old.
Button though claims he has now resolved his differences with BAR following a meeting with Richards today.
In a statement released through his management company Button said: "Given the circumstances, the meeting was constructive.
"David is now in no doubt of my intention to return to BMW Williams in 2005. My contractual position allows for this.
"I have also clarified that I am not moving for money, and my motivation is straightforward determination to win a World Championship, determination which I am sure he as a competitive person well understands.
"Naturally, the main element of disagreement is whether these ambitions would be better served by BMW Williams or BAR, but I have made my decision."
Button was given his first opportunity in Formula One by Williams before moving on to Renault and then BAR.
He has enjoyed a successful 2004 season to date and currently lies third in the World Championship after a career-best second place in the last Grand Prix in Germany.
His success attracted the interest of Williams and Button, who claimed he had fulfilled his contractual obligations with BAR, feels there should not be a problem with the move.
BAR claimed they wanted to up an option of a year's extension with the driver.
Button added: "I have worked hard and contributed seven podiums and 61 of the team's 76 points this season.
"Drivers are changing teams up and down the paddock at the moment - an accepted and fundamental element of our sport - and I wish that my return to Williams would have been less acrimonious in light of the contribution I have made to BAR this season."