A private equity firm has gained an unprecedented influence over European rugby after striking a deal worth more than £300 million for a share in the Six Nations.

CVC Capital Partners, which has already bought a stake in the Gallagher Premiership and has nearly completed a similar deal with the Guinness Pro14, has agreed in principle to buy a 15 per cent share in the six unions’ commercial arm.

The European countries have decided to pool their businesses into one commercial entity, meaning that the private equity firm will own a share not only of the Six Nations Championship, but also the autumn internationals and summer tours.

All sides expect the deal to be completed after the World Cup. The Pro14 deal should be finalised