W & G Investments, which is hoping to buy the branches for £1.1bn, has disclosed its backers in documents filed ahead of its intended listing on the Aim market this week.
Schroders, Threadneedle and Old Mutual are among the big backers for W & G, led by former Tesco finance director Andy Higginson, which has raised an initial £15m, and the full £1.1bn fundraising is said to have been oversubscribed.
Toscafund, run by Martin Hughes, was one of the main drivers of the break-up and sale in 2007 of ABN Amro, in which it held a 2% stake.
It currently is the biggest institutional shareholder in online dating group Cupid with over 10% of the shares.
Meanwhile, Lloyds Banking Group is reported to be in talks with German insurer Hannover Re for the sale of its German insurance business, for less than half the £850m it had hoped to achieve when starting the process two years ago.