The Commonwealth Bank has posted an unaudited profit of around $1.8 billion for the three months to September.
In its quarterly trading update, the bank says its interest margins had remained stable overall, however it had increased margins in its retail banking business, and lower commercial banking margins.
CBA's bank's preferred measure of cash earnings was broadly in line with the estimated statutory profit, at $1.85 billion.
The cash earnings result is just under 6 per cent higher than it was in last year's September quarter update, when the bank posted unaudited earnings of $1.75 billion.
CBA says it has managed to restrain costs to maintain its profitability.
It also notes that loan arrears and bad debts have been stable to slightly lower, with impaired loans making up about 21 basis points of the total portfolio, or about $291 million.
CBA says its loan growth remains largely funded by deposits, which now account for 63 per cent of total funding.