Moneysupermarket said the unsolicited bid, which has not been identified, was rejected by the firm's chief executive and majority shareholder Simon Nixon.

The firm's shares soared by nearly 50 per cent yesterday. The stock had jumped more than 10 per cent earlier in the day.

Earlier this month shares in the Ewloe-based company fell more than 32 per cent after it revealed a potential £7 million revenue blow due to First Plus, stopping new business.

The stock had not recovered from the slump.

The firm said: "The board of the company notes the recent movement in its share price and confirms that an initial approach regarding a possible offer for the company was today made to Simon Nixon... in his capacity as 54 per cent shareholder in the company.

"The unsolicited approach did not contain indicative terms for any offer and has been rejected by Mr Nixon."

Moneysupermarket has seen business from its loans and mortgage division worsen this year as lenders have tightened up their loan criteria. But the company has enjoyed strong growth in the credit cards and savings area.

The group said that its money arm revenues – which makes up more than half of group turnover – would deliver "high single digit" growth compared to the same period last year.

Total visitors to Moneysupermarket's website soared by more than 50 per cent to 91 million during last year, with the number of transactions up by a similar level to 58.2 million.