High profile Abu Dhabi investors have been in talks concerning a £10bn investment into Royal Bank of Scotland it was alleged on Wednesday.

Shares in the UK bank rose sharply by 4.6 percent in early trade following the news that Abu Dhabi's ruling family including Sheikh Mansour and other Abu Dhabi and Middle Eastern investors could invest up to £5bn in RBS stock.

As much as a third of RBS could be sold to Abu Dhabi wealth funds but shares are still short of the average 49.9 pence the UK government paid for its stake. Critics say a sale at the current share price would therefore leave UK taxpayers with billions of pounds in losses.

Discussions have been ongoing for several month and the deal could happen by the end of this year sources familiar with the matter indicated.