Formula One Group's new majority owners have strengthened their grip on the sport by raising their stake in the controlling company to 86%.
The Alpha Prema business, set up by private equity firm CVC Capital Partners and Bernie Ecclestone, has done so by buying out bank JP Morgan.
It now leaves only one other remaining shareholder, fellow US bank Lehman.
Mr Ecclestone remains chief executive of the Formula One Group, with an unspecified stake.
The 75-year-old has made a fortune from exploiting the rights to the sport.
Yet the sport is still facing an uncertain future, with carmakers threatening to break away and set up a rival championship in 2008 unless significant changes are made to the way the sport is run.