Liberty Media has bought a further 0.4% stake in F1, increasing its overall holding to 19.1%.

The 0.4% stake was acquired on 27 October for $13m and follows September's purchase of the initial 18.7% stake in F1 for $746m in cash.

In total, Liberty Media now owns 19.1% of Delta Topco, F1's parent company, which is controlled by CVC which owns 38.1%.

Thus far, Liberty Media has not bought any of CVC's shares but once the necessary regulatory and shareholder approval is given control will switch to the American company.

According to Forbes, the original $746 million was funded with cash and borrowings including the sale of debentures which are convertible into Time Warner stock.

Time Warner is one of many companies which Liberty owns shares in. The others include media company Viacom, the Atlanta Braves baseball team and event promoter Live Nation. It has been using the shares as a guarantee to raise the money which it is buying F1 with.

Liberty's offer values F1 at £3.3bn but it needs more than cash to take over F1 completely. Liberty also needs consent from its shareholders, Britain's Competition and Markets Authority and F1's governing body the FIA.

The latter has been the subject of significant concern as it stands to gain £33 million if the sale goes ahead. This is because the FIA owns a 1% stake in Delta Topco which it was sold for £270,000 in 2013 and comes with the catch that it can only be sold when CVC sells its shares.

It raises the question of whether the FIA has a conflict of interest and MEP Annaliese Dodds has written to the European Commission calling for an investigation into this.