Goldman Sachs is reportedly set to advise the government on the sale of its remaining stakes in Britain's bailed-out lenders at the same time as one of its divisions tries to buy billions of pounds of bank assets from the taxpayer.According to Sky News, Goldman was hired as the privatisation adviser to UK Financial Investments (UKFI) just days after Chancellor George Osborne announced that he would begin selling the government's shares in Royal Bank of Scotland within months.Goldman will replace JP Morgan as UKFI's privatisation adviser, and will assist the Treasury agency with its plans for placing billions of pounds of shares in Lloyds Banking Group and RBS.Sky pointed out that the appointment may be controversial, given Goldman's role advising the Treasury on the nationalisation of Northern Rock in 2008, and its securities division's interest in buying Granite, which is a £13bn mortgage portfolio put up for sale by Osborne earlier this year.