AUSTRALIA'S top finance regulator has written to bank executives telling them not to turn a blind eye to lending risks even when it comes to banks giving customers so-called hardship concessions.

The letter, sent by the Australian Prudential Regulation Authority, comes as a slowdown in parts of the economy has led to rising job losses.

Meanwhile, some banks are still working through the impact of natural disasters on their balance sheets, including last year's floods.

But the big banks are expected this week to confirm they are on track to deliver in excess of $24 billion in annual earnings this year.

Banks can give customers with temporary financial difficulties hardship concessions. This typically includes a reduction in the interest rate or payment, lengthening of loan maturity, or full or partial deferral of interest for a temporary period.