Fred Done, who founded the 1,650-strong chain of bookmakers with his brother Peter, is in talks to offload 25% of the on-course betting business.

The proposed deal — first reported by Sky News — would value the Tote at about £150m and crystallise a paper loss for Betfred.

The company paid £265m to take the Tote off the government’s hands in 2011, when it was granted a seven-year monopoly on British racecourses. Its exclusive rights expire this summer.

Some of Britain’s best-known racetracks, including Aintree, Cheltenham and Goodwood, are planning to launch a rival business. Mr Done is said to have been approached in recent months by several consortia keen to buy part or all of the Tote, ‎but is only thought to have become seriously engaged with the investors he is now close to striking a deal with.

The group ‎in negotiations with the Betfred tycoon is understood to be led by Eamon Wilmott, the chairman of Total Performance Data, a provider of technology used in horseracing around the world.

Mr Wilmott, who was on the board of the British Horseracing Authority until last November, is said to be in line to become the Tote’s chairman‎.

Its chief executive would be Alex Frost, a former Merrill Lynch banker, according to insiders.

The consortium is understood to have pledged tens of millions of pounds to invest in marketing the Tote‎ if it convinces Mr Done to sell the stake.

If concluded, the deal will represent another chapter in the 90-year history of the Tote, which was set up partly at the instigation of Winston Churchill, the future Prime Minister, who at the time was a racehorse-owning Chancellor of the Exchequer.

It remained government-owned until Mr Done persuaded ministers to sell it to him in 2011.

The Betfred founder, who along with his brother was said to be worth £1.33bn‎ by last year’s Sunday Times Rich List, is one of the British gambling industry’s most successful entrepreneurs.

His business now operates more than 1,650 shops across the country.

Speculation last year suggested that Mr Done was examining a stock market flotation of Betfred, although that idea was dismissed at the time by people close to the company.