The Royal Bank of Scotland confirmed Wednesday it was in late-stage settlement discussions with authorities in a LIBOR investigation and expects to pay 'significant penalties'.RBS said it was in final talks with regulators in the Britain and the US in relation to a probe into interest rate rigging."Although the settlements remain to be agreed, RBS expects they will include the payment of significant penalties as well as certain other sanctions," the bank said in a statement."RBS will update the market on all pertinent issues relating to this matter shortly."The bank, which is 81% state owned, is expected face criminal charges and a £500m fine for its role in the LIBOR scandal. RBS is one of about 20 banks under investigation for involvement in manipulating the rate, which governs the price of loans and transactions around the world, including household mortgages. Barclays was recently fined £290m by US and UK regulators. The statement from RBS comes a day after it emerged investment banking boss John Hourican was resigning at the end of the month. RD