Williams chairman Adam Parr has resigned and will leave the Formula One team later this week, it was announced on Monday.
The British outfit gave no reason for Parr's surprise decision to step down beyond team principal Frank Williams saying he was seeking a "better balance in his life".
"Williams Grand Prix Holdings PLC today (Monday) announced that its chairman Adam Parr has resigned from the company," said a team statement.
"Adam will leave Williams on Friday 30 March 2012."
Parr joined Williams in 2006 as chief executive officer and two years ago became chairman stepped up to the position of chairman in 2010.
He had been tipped by Frank Williams to one day succeed him and the founder of one of Grand Prix racing's most successful teams paid tribute to Parr by saying Monday: "Adam's achievements have surpassed my expectations and I must thank him for his service."
"Adam leaves us on good terms to pursue a better balance in his life for which I wish him and his family well."
"He has left us in good shape and I have every confidence that the Board and senior management team at Williams will continue to drive the business forward into a promising future."
Williams have shown signs of progress this season after a poor 2011 campaign, and saw driver Bruno Senna, nephew of late former world champion Ayrton, finish sixth and in the points in last weekend's Malaysian Grand Prix.
They have won 113 Grand Prix and lifted the constructors' world championship nine times but last season scored just five points.
However, Parr said he expected Williams, based in Grove, southern England, to build on their recent progress in his absence.
"I am very grateful to Frank for giving me the opportunity to work for Williams over the past five years - a period that has been both challenging and rewarding," he said.
"Williams is now set up to move forward and I wish everyone at Grove well."
Williams said Nick Rose, a non-executive director of Williams Grand Prix Holdings, would be appointed non-executive chairman, with Frank Williams continuing as team principal.