Stephen Hester, the head of part-nationalised lender Royal Bank of Scotland, is to leave later this year as the government prepares to sell off its 81 per cent stake in the bank.In an announcement after the close of trade on Wednesday, RBS announced that it has started its search for a new Chief Executive Officer (CEO) and that an "orderly succession process will give a new CEO time to prepare the privatisation process and to lead the bank in the years that follow".The bank said that Hester was "unable to make that open-ended commitment" after five years in the job already.He is to receive payment in lieu of notice of £1.6m representing 12 months' pay and benefits, but will not get a bonus for 2013, the bank said.Hester was appointed CEO in November 2008 after the government bailed out the bank along with Lloyds during the financial crisis. After a massive restructuring plan and making "huge progress in becoming a strong bank", RBS said that there was a "window to begin a transition of leadership" ahead of the government sell-down."It has been nearly five years since I joined RBS after the bank was rescued by the government," Hester said in a statement. "In that time we have reduced the bank's balance sheet by nearly a trillion pounds, repaid hundreds of billions of taxpayer support, and removed the imminent threat that this bank's size and complexity posed to the UK economy. All the while we supported 30 million customers every day to help them manage their finances."