Royal Bank of Scotland (RBS) is set to sell the international branch of Coutts, its private bank, in a deal thought to be valued at around $1bn (£600m), Reuters news agency said on Monday.RBS's decision will see Coutts split into two separate businesses, with one to be based in Britain and one to be based in Zurich, from where it'll manage operations in Dubai, Abu Dhabi, Singapore and Hong Kong.Operations in the Middle East and in Far East Asia are worth almost $36bn (£21.4bn) and Reuters reports RBS has already attracted offers from a host of bidders for Coutts International, including unspecified North American and Asian businesses.RBS could make between $720m (£429m) and $1.1bn (£660m) from the sale, a source told Reuters.Coutts' international division has already cut the number of countries it served and RBS said Coutts should sit within RBS's own commercial and private bank, in order to better connect with that unit's wealthy entrepreneurs and other potential clients."As part of the transition and integration of this business, we have been reviewing our private banking business so that it works for the benefit of our customers," RBS said last week.RBS' overhaul of Coutts, founded in the 18th century and known as banker to the Queen of England, is part of its strategy to pay back taxpayers' funds and return to private ownership, following a £45bn rescue in the wake of the financial-crisis.The bank is 81% owned by the state and posted £1bn quarterly profit recently.RBS shares were down 1.91% to 339p at 12:44 on Monday.DC