By Jonathan Davies

The Royal Bank of Scotland (RBS) has sold its overseas arm Coutts International to Swiss bank Union Bancaire Privee (UBP).

A Coutts spokesperson said that both RBS and UBP had agreed not to disclose the value of the deal. The Financial Times estimated it to be worth $600-800 million.

RBS has owned Coutts International since 2000, but the sale is part of the bank's policy to sell-off international assets to focus on the UK. The bank will retain Coutts' UK business, which has the Royal family as customers.

UBP's assets nearly halved during the financial crisis, and this is its first major purchase since it bought Lloyds Banking Group's overseas arm in 2013.

UBP's chief executive said in a statement: "This acquisition confirms our commitment in further developing our wealth management business and represents a significant milestone in our growth strategy."

"Last year we set out a clear strategy to create a truly UK-focused bank," said Alison Rose, chief executive of RBS's commercial and private banking unit.

"This announcement is another important step in that process. Following an extensive review, it was clear that the bank we are building would not be the most appropriate owner of the business being sold."