Spread-betting tycoon Stuart Wheeler is selling his stake in financial bookmaker IG Group because he wants to renovate his castle in Chilham, Kent.

IG Group, the company founded and chaired by Mr Wheeler, could now become a potential takeover target.

Mr Wheeler's 23.68% stake is currently worth about �25.5m ($41m).

I am nearly 68, at that age it is pretty mad to have almost all your assets in one company Stuart Wheeler

The 67-year-old founder and chairman of IG Group, who is also a major Conservative Party donor, added that he wanted to give some of the money to charity.

"I am nearly 68. At that age it is pretty mad to have almost all your assets in one company," he told BBC News Online.

"It is a rather sad decision, but I am moving into a castle and the renovation and decoration costs are more than I had anticipated.

"And once you move in there are high running costs as well."

Political donation

Mr Wheeler said he had not been approached by any potential bidders.

He added that other long-standing shareholders were also considering selling their stakes in IG Group.

The total number of shares that might be sold "is likely substantially to exceed 30%" of the company, IG said.

"Some shareholders are sitting on huge profits. The company was set up with an investment of only �30,000 and their stake could now be worth millions."

Mr Wheeler refused to comment on what his company could be worth: "That is very hard to say."

Last year he gave �5m to the Conservative Party.

His donation was controversial because he said he would not support the Tories if the pro-European former chancellor Ken Clarke were to become party leader.

Spread-betting on sports

Mr Wheeler, who is married with three daughters, was a barrister before he set up IG Index in 1974.

The company allowed UK residents to speculate on the price of gold at a time when exchange controls prevented them from buying it, except at a premium.

Over the years, IG's betting business was expanded to include all commodities in the London market, then the US markets, FTSE and Dow Jones indices and other financial figures, such as stock index futures.

In 1993, the company set up a department to take spread bets on sporting events. It was a new sector which sky-rocketed during the 1990s to become a highly profitable part of the betting industry.

IG's first non-betting activity began in 1996, when the company started dealing in foreign exchange.