Royal Bank of Scotland has reported a £469m loss for the July-to-September period as "legacy issues" continue to overshadow its performance.
The bank received a £45.5bn bailout during the financial crisis and has been tackling a range of problems.
But once restructuring costs and provision for litigation were excluded, the bank made an adjusted quarterly operating profit of £1.3bn.
It said it could not sell its Williams & Glyn bank by the end of 2017.
RBS has been ordered by the European Commission to sell Williams & Glyn in order to prevent the group from having too dominant a position as the UK's largest lender to small businesses.
Earlier this week, Clydesdale Bank confirmed that it had made an offer for Williams & Glyn after Santander abandoned plans to buy the business.
RBS declined to comment on Clydesdale's statement, saying only that it was "talking to a number of interested parties".
However, RBS said it did not expect to expect to sell off the business by 31 December 2017, as the Commission requires.
RBS has already missed an earlier deadline for the sale, of November 2013, without incurring any punitive action by the Commission.
RBS is still 73% owned by the government following its emergency bailout in 2008.
Its latest attributable or "bottom-line" loss was widened by restructuring costs of £469m and conduct and litigation costs of £425m, as well as a deferred tax write-off of £300m.
The third-quarter loss compares badly with the same period last year, when RBS posted a profit of £940m. But that was flattered by proceeds from the sale of US bank Citizens.
Unlike Lloyds and Barclays earlier this week, RBS has made no new provision for costs arising from mis-selling of Payment Protection Insurance (PPI).
The new litigation costs have been set aside in readiness for expected liabilities in the US, where the bank faces charges in relation to the sale of mortgage-backed securities in the run-up to the financial crisis.
RBS said these were among "a range of uncertainties in the external environment".
RBS chief executive Ross McEwan said: "We've said that 2015 and 2016 would be noisy as we work through legacy issues and transform this bank for customers. These results reflect that noise.
"Our core business results were good, with a £1.3bn adjusted operating profit, our best quarter since 2014.
"The core business has now delivered on average over £1bn in adjusted operating profit for the last seven quarters."
RBS said it had achieved cost reductions of £695m in the first nine months of the year and was on target to meet its target of an £800m reduction by the end of this year.
"RBS has yet to emerge from the weight of misconduct fines, restructuring costs, the distraction of the sale of the Williams & Glyn unit, the spectre of the government stake and the lack of a dividend payment," said Richard Hunter, head of equities at Wilson King Investment Management.
"Meanwhile, the bank's longer term targets have also been temporarily shelved in the face of its ongoing challenges."