Europe's largest bank, HSBC, has decided to close its retail banking operation in Russia and concentrate on servicing corporate clients, a document obtained by Reuters showed on Monday, April 25.

"We encourage all customers to close their HSBC Premier and HSBC Plus accounts before June 30, 2011," the document said.

HSBC will follow British Barclays, which earlier this year said it will sell its Russian unit and focus on investment banking, as it was unable to compete in local retail business.