Barclays says it has set aside an extra £600 million to meet compensation claims for mis-selling of payment protection insurance (PPI) in the third quarter.

The sum exceeds some banking expert estimates for £500 million in the three months to September and brings the total provision over the past two quarters alone to £1 billion, after £400 million was put aside in the second quarter.

The banking industry's PPI bill already stands at more than £30 billion.

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The Financial Conduct Authority (FCA) has put a June 2019 deadline on claims in an effort to draw a line under what has been one of the biggest banking scandals in history.

Barclays' statutory profit before tax was up 35% to £837 million in the third quarter.

Net operating income fell to £4.7 billion in the quarter, from £5 billion in the same period last year.

Chief executive Jes Staley said the bank's is still focused on selling down and disposing of its hinterland businesses as quickly as possible to focus in on US and UK operations

Mr Staley added: "The growing momentum in attaining our strategic goals means we can feel optimistic of our prospects of completing the restructuring.

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"Our core businesses are performing well, non-core rundown is approaching the final lap toward closure, we are on top of costs, and our capital position is resilient with strong reasons for confidence in meeting our end state target."

Barclays earlier this month announced plans to sell its Egyptian business to Attijariwafa Bank for a price understood to be about 500 million US dollars (then £392 million).

The overhaul has also seen the lender sell its Barclaycard credit card operations in Spain and Portugal to Bancopopular-e and sell down its 62.3% stake in Barclays Africa.

In August, the bank also sold its risk analytics and index unit to Bloomberg for about £615 million.

"Taken together, the picture in the third quarter is one of strong progress against this agenda," the chief executive said.

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Barclays also said that the group's main pension scheme deficit ballooned to £1.1 billion from an £800 million surplus.

However, the bank said that the pain of PPI provisions and the pension deficit was partially offset by "favourable" currency moves, following the devaluation of the pound in the wake of the EU referendum.

Sterling has fallen nearly 20% against the US dollar since the Brexit vote, aiding multinational firms like Barclays which benefit from income in stronger foreign currencies.

The bank's currency translation reserve grew to £2.4 billion as of September 30, from £1.7 billion at the end of June.