Just over 8%, or 62,970, of private mortgages in Ireland are in arrears of more than 90 days, according to official figures from the Central Bank.
The number of mortgages in difficulty has increased since June when 55,763 were in arrears.
The amount of mortgage arrears now outstanding for 90 days or more has also passed €1 billion for the first time. The average size of the arrears is just over €17,000 and the average loan amount outstanding is €196,400.
46,371 mortgages have been in arrears for more than 180 days. Their arrears amount to almost €994m. Mortgage holders in arrears for more than 180 days are, on average, €21,000 behind in their repayments.
A total of 76 repossession orders were granted by the courts between July and September and 162 homes were taken possession of by lenders.
Today's Central Bank figures also indicate there were 119 voluntary surrenders or abandonment of properties in the same period. Just over 1,000 properties have repossessed in the past two years.
There are currently 773,420 private mortgage accounts held in Ireland to a value of €114.4 billion.
Total restructured mortgages were 69,735. At the end of June 66,732 restructured mortgages were listed.
Of the restructured mortgages, where people have lengthened the term or opted for interest-only periods, 36,376 are sticking to the new arrangements. 33,359 restructured mortgages have slipped into arrears of varying degrees.
This means that 99,346 mortgages are either in arrears or have been restructured.
New Beginning - a campaign group set up to help those struggling with mortgages - says it is clear that the mortgage crisis continues to worsen.
It said it reiterated its call for a coherent solution from the Government to the arrears problem, "without which there will be no economic recovery in this country".
Reacting to today's Central Bank figures, the Irish Banking Federation noted that the level of repossessions still remains comparatively low - 21 per 100,000 mortgages here compared to 82 per 100,000 in the UK.
The federation said it continues to strongly encourage borrowers who are under pressure with their repayments to communicate with their lenders to find a solution.
Most in negative equity not in arrears
The Central Bank has published additional new research on mortgage arrears and negative equity, which shows that just over a third of households with mortgages are in negative equity - where they owe more than the value of their home.
More than half of borrowers who took out mortgages between 2005 and 2008 are in negative equity. But the bank said 90% of those in negative equity have not so far fallen behind with their mortgage repayments.
One-third of the mortgages examined from the four main lenders - AIB, Bank of Ireland, EBS and Permanent TSB - were given out in the boom years between 2005 and 2008. Only 5% of these were in arrears.
The Central Bank research - which covered 600,000 loans - also indicates that just over half of buy-to-let properties are in negative equity. The average negative equity in these cases is just over €100,000.
56% of mortgages in arrears for more than 90 days were with AIB, Bank of Ireland, EBS or Permanent TSB. 35% of loans in arrears were with other mortgage lenders, while 9% were with sub-prime lenders.
The bank also found a higher level of arrears among homeowners with standard variable rate mortgages. 16% of these were behind with their repayments, with 6.3% in arrears for more than 90 days. For tracker mortgages, the figures were 12% and 4.2% respectively.
"This implies that 10% of properties on standard variable rates, which have already experienced some level of arrears, could experience long-term arrears if standard variable rates were to increase significantly," the bank said.
The Central Bank research also found that around a quarter of homeowners have more than one loan secured against their property.
Two-thirds of households with mortgages owe less than €200,000, while another 30% have debts of between €200,000 and €500,000. Less than 4% owe more than €500,000.