Go Compare, the insurance price comparison site fronted by fictitious opera singer Gio Compario, is up for sale for at least £275m.
Documents published by motor insurer Esure confirm that the business is available to suitors just months after the Independent on Sunday revealed that Grant Thornton had been appointed to advise its founder Hayley Parsons on a potential disposal.
Go Compare is 50 per cent owned by Ms Parsons and other directors at the group. The remaining stake is controlled by Esure, which is planning to list on the London Stock Exchange later this month.
The adviser Evercore has been appointed to work on the sale. The minimum £275m price is believed to be much lower than Go Compare's owners would actually accept, although the process is believed to be at a very early stage.
Private equity firms, rival price comparison sites and even the search engine Google have been linked with the company. The news was disclosed in Esure's initial public offering prospectus, which revealed that Esure expects to be valued at up to £1.3bn when it lists on the London Stock Exchange.
The motor insurer, which owns Sheilas' Wheels, the product aimed at women drivers, set a price range of 240p to 310p for the flotation, which will be the largest in the City this year once it is completed this month.
Banks and other advisers are expected to pick up less than £10m in fees, a fact that will please potential City investors.
Stuart Vann, the chief executive, said ahead of an investor roadshow: "Our 2012 results were excellent, and investors will clearly look at that and make their own decisions.
"We will be seeing [investors in] a lot of different markets over the next two weeks so it is a very exciting time for us, very busy but very exciting."
Esure plans to raise about £50m by going public, which it will use to pay off debt and fuel growth. The move could eventually net its founder, Peter Wood, up to £200m although he will remain as the company's largest shareholder .
He said: "We live and breathe insurance at Esure and look forward to bringing that knowledge, commitment and focus to bear as a premium-listed company."