NAB's results at a glance

National Australia Bank reported a net profit of A$2.05 billion for the six months to March 2012 - down 15.5 per cent on the previous corresponding period.

Profit was down 26.5 per cent in the six months since September 2011.

Earnings per share fell 18.4 per cent year-on-year, and fell 28.6 per cent half-on-half.

The bank said the fall in earnings reflected higher charges for bad and doubtful debt, impairment of goodwill and capitalised software. There was also an additional provision for potential claims relating to payment protection insurance in the UK banking division.

The charge for bad and doubtful debts was $1.1 billion - an increase of 14.5 per cent over the previous corresponding period and an increase of 35.6 per cent over the September half. Most of the increase came from the UK banking division.

The bank's preferred profit measure, unaudited cash earnings, rose six per cent, to $2.8 billion. The cash earnings figure was arrived at after adjusting statutory profit for charges related to the recent UK strategic review and hedging costs.

Unaudited cash earnings rose 1.3 per cent in the six months since September.

Cash ROE fell 10 basis points to 15 per cent.

Revenue was $9.1 billion - a 3.5 per cent increase year-on-year and an increase of 3.6 per cent half-on-half.

The bank's group net interest margin rose from 2.23 per cent in March last year to 2.28 per cent in September but then fell 11 basis points to 2.17 per cent in the latest half.

In the business banking division, NIM rose from 2.57 per cent in March last year to 2.66 per cent in September but then fell to 2.56 per cent in the latest half.

In personal banking, NIM took a big fall - down from 2.22 per cent in March last year to 2.17 per cent in September, and then down to 2.02 per cent in the latest half.

The core Tier 1 capital ratio was 8.03 per cent - up from 7.58 per cent in the previous half.

Among the divisions, business banking was flat half-on-half, with cash earnings of $1.3 billion. Business banking contributes close to half total group earnings.

Earnings for personal banking were down 7.2 per cent half-on-half, to $464 million. The division's return on assets was 0.65 per cent (down nine basis points half-on-half). The cost to income ratio rose from 51.5 per cent in the September half to 52.1 per cent in the latest half.

Wholesale banking cash earnings jumped 93 per cent half-on-half, NAB Wealth was up 11 per cent and New Zealand was up 17 per cent, but UK banking made a loss of A$25 million.