(Corrects headline and text to show all figures in U.S. dollars not Australian dollars)
Jan 23 (Reuters) - Australia's biggest insurer QBE Insurance Group QBE.AX said on Tuesday it expects to report a full year after-tax loss of about $1.2 billion, hurt by impairment charges in its North American operations.
The company flagged in a statement that it expects its combined operating ratio (COR), a percentage of claims payouts against premium income, could rise to 104 percent, above the target COR range of 100-102 percent.