W&G said it has been in non-exclusive discussions with RBS since early 2013 and had already made a non-binding proposal. It will offer 1.1 billion pounds upfront, raised by a placing of new shares, with a further 400 million pounds to come from future profits. W&G has backing from institutional investors including fund manager Schroders ( UK: SDR), and reportedly also peers such as Threadneedle Asset Management, Aviva ( UK: AV), and F&C Asset Management. W&G's directors, led by its non-executive chairman and former chairman of the retail banking business of Tesco ( UK:TSCO), Andrew Higginson, have been aggressively suggesting that their structure is superior to that proposed by the two competition private equity consortia. The rival bidders are a club approach of AnaCap Financial Partners and Blackstone Group ( BX), and another grouping of Corsair Capital and Centerbridge Partners , which is reportedly also backed by the Church of England's investment fund, Standard Life ( UK: SL)\, and a Rothschild investment fund. The private equity consortia have offered smaller amounts upfront, reportedly 600 million to 800 million pounds in the case of Centerbridge and Corsair, and would float the business at a later date -- possibly as late as 2015 -- when the carve out from RBS is complete. John Maltby, the former Lloyds Banking Group ( UK: LLOY) executive who heads the Corsair bid, has reportedly said an IPO would ultimately leave the U.K. government, which currently owns 83% of RBS, with more upside than an immediate sale at book value. RBS, which suffered a big setback in its plans to dispose of the branches after agreed bidder Banco Santander ( BCDRF) scrapped a 1.65 billion pound deal last October, is also contemplating a demerger and initial public offering of Williams Glyn as an alternative to a sale.