Insurance giant QBE has flagged a half-year net loss after tax of $US750 million ($A1.1 billion), reflecting the impact of the COVID-19 pandemic, higher claims and a loss on its investment portfolio.

The company had reported a first-half profit of $US463 million a year ago.

It said the pandemic has adversely affected multiple lines of its business, with higher claims expected due to business interruptions, health problems, higher casualties and a deterioration in credit.

This will result in an underwriting impact of around $US335 million for the six months ended June, QBE said. It said the combined operating ratio – or claims paid against premium earned – had blown out to 104 per cent.

In addition, the company expects further net claims of around $US265 million to emerge over the next 12-18 months, primarily in the trade credit and lenders mortgage insurance segments.

The insurer said it currently estimates total COVID-19 related costs to be around $US600 million ($A848 million) on a pre-tax basis, but warned that the business landscape remains highly uncertain.

It has also suffered a net investment loss of about $US125 million, caused by “extreme investment market volatility” during the period.

“Despite the impact of COVID-19, I am encouraged by the strong underlying trends evident in the result,” group chief executive Pat Regan said.

“We are supporting customers through various initiatives including premium refunds, premium deferrals, extending credit and counselling services to vulnerable customers and accelerating claims payments,” he added.

The insurer said its capital position remained strong, with debt-to-equity ratio at around 30 per cent as at June-end, and liquidity of around $US1.5 billion.

QBE in April raised $A1.3 billion from shareholders to build a buffer against the impacts of the coronavirus pandemic.

By 1250 AEST, shares in the insurer were up 1.5 per cent at $9.82 in a weak Australian market.

The company will report its half-year audited results on August 13.