As the top company at Williams is publicly traded on a stock exchange they have to publish more details to the markets:
"Williams Grand Prix Holdings PLC (WGPH, Ticker: WGF1) is today pleased to announce the completion of the sale of Williams Grand Prix Engineering Limited ("WGPE"), the operating subsidiary of the Group, to BCE Limited, a fund managed by Dorilton Capital Management LLC for €152 million (the "Transaction"). WGPE consists of the Formula 1 business, the minority stake in Williams Advanced Engineering, and all other trading assets and liabilities including all third party indebtedness of the Group."