National Australia Bank Ltd.'s fiscal third-quarter cash earnings declined 3% year over year to A$1.65 billion.

The bank attributed the decline to higher investment expenses and credit impairment charges. Expenses grew 2% partly due to higher compliance costs and increased depreciation and amortization, while credit impairment charges increased 9% to A$203 million.

The gross impaired assets ratio was steady from the previous quarter at 0.71%, but dropped from 0.80% in the year-ago period.

On a statutory basis, unaudited net profit was A$1.65 billion.

Revenue for the quarter rose 1% due to growth in small and medium enterprise lending within the bank's business and private banking segment and strong contribution from its New Zealand banking operations.

The bank said net interest margin declined slightly reflecting elevated short-term wholesale funding cost and ongoing intense home loan competition.

The groups' common equity tier 1 ratio clocked in at 9.7% as of June 30, compared with 10.2% in the previous quarter and with 9.7% in the same period in the 2017.