Jenson Button's Formula One future has moved closer to a resolution after Williams lodged a contract they hope will confirm the driver's switch from BAR.
A Williams spokesman said the team had deposited the necessary paperwork with Formula One's contract recognition board (CRB).
BAR, who do not want Button to leave, have also lodged a contract. Williams' move will now leave in the hands of the Swiss-based board the decision as to which team has the right to the 24-year-old's services next year.
Depending on the date of a hearing, yet to be decided, the CRB could rule on the matter by the end of September.
Button announced he was leaving BAR last month, a shock decision that stunned the Honda-powered team and pitched them into a tug-of-war with Williams.
BMW-powered Williams, who gave Button his Formula One debut in 2000, believe that their two-year deal with the Briton is water-tight.
The team spokesman said they had delayed registering the contract while private negotiations to resolve the situation were ongoing.
The delay in filing a contract had triggered fears that the dispute between the two teams could rumble on well beyond the end of the current season in October and end in a battle through the law courts.
Williams have also signed Australian Mark Webber from Jaguar in an all-new line-up for 2005 to replace departing Ralf Schumacher and Juan Pablo Montoya.
Button, who escaped unhurt from a big crash at the last Belgian Grand Prix, is third in the championship with four races remaining.