Sunderland's estimated worth revealed following promotion to the Championship

Dr Daniel Plumley, of Sheffield Hallam University, says the Black Cats’ income will increase by around £10million per year after beating Wycombe Wanderers in the League One play-off final, ending a four-year spell in the third tier.

Sunderland’s ownership structure remains complicated, though, with majority shareholder Kyril Louis-Dreyfus owning just 41 per cent of the club.

Supporters were quick to voice their dissatisfaction when it was revealed earlier this year that former chairman Stewart Donald has retained a 34 per cent stake, with Juan Sartori and Charlie Methven holding 20 per cent and five per cent respectively.

Donald and Methven have said they are prepared to sell their combined 39 per cent shareholding for £11.7million, equating to a club valuation of £30 million - yet that was when the club was in League One.

“In the Championship I would probably add another £15-20million on that valuation,” Plumley told the Echo earlier this month.

“Obviously if you jump into the Championship and your revenue boosts by £10million and you’ve got extra commercial leverage and more exposure, you should be setting that price a little bit higher as well.

“Of course if you get further up you can add another £100million (in the Premier League) onto that again so it does scale up with the leagues that they are in.”

Methven has said himself and Donald have continued to make pro rata financial contributions based on their shareholdings.

And while the club’s revenue will increase in the Championship, more money will have to be spent on wages and transfers to compete in England’s second tier.

Football finance expert Kieran Maguire told the Echo last month: “If Stewart Donald wants to maintain the proportion of shares that he owns, then for every pound Louis-Dreyfus puts in then Donald and Methven have to put money in as well - that just makes things a little bit messier.

“He (Louis-Dreyfus) could certainly lend money to the club to fund transfers or he could come to an agreement with Donald, Methven and Co that he could put more money in in the form of shares and that will increase his stake.”