The world's largest insurer, American International Group, has posted its largest ever quarterly loss.

The result has confirmed the second consecutive quarterly loss for AIG, which has been hurt by a write-down of derivatives exposed to bad mortgage investments.

AIG said the first-quarter net loss was US$7.81 billion, compared with net income of US$4.13 billion a year earlier.

AIG said it expected to raise US$7.5 billion of the total capital through a common stock offering.