Junior bondholders of stricken UK mortgage lender Northern Rock are facing heavier losses on the securities they hold amid uncertainty over the successful completion of a rescue plan from a potential bidder any time soon, according to analysts.

Northern Rock has just under £2.6bn (€3.6bn) of outstanding subordinated debt, of which investors hold close to £1.9bn of junior subordinated debt or preferred stock, according to data from rating agency Standard & Poor's.