Prudential could be set to auction off its 79 per cent stake in Egg after the insurer said it had received a number of approaches.
The announcement comes a week after it emerged that Prudential was in discussions over a possible sale, expected to value Egg at more than £1.5 billion.
The Prudential said those talks continued but that it had received "unsolicited indications of interest from a number of other parties". It added: "Prudential has now begun a process that will give a number of potential purchasers an opportunity to make a proposal. This may or may not lead to a transaction."
Credit card issuer MBNA and the Royal Bank of Scotland are among groups thought to be interested in making a bid for Egg, which employs 2,600.
Despite strong growth in its British business, the online bank recorded losses of £48.7 million sterling last summer because of difficulties at its French business.