Asian markets open lower on US downgrade

Asian stocks fell in early trade today before clawing back some of their losses following frantic weekend efforts to calm financial markets after a downgrade to the United States' credit rating.

The slide came after financial chiefs and central bankers of the G7 nations pledged to "take all necessary measures" in coordinated action to support stability and the European Central Bank said it would buy up eurozone debt.

Tokyo opened 1.40%, or 130.21 points, lower at 9,169.67 before recovering slightly in the morning while Seoul was also 1.40% lower at the open, falling 27.18 points to 1,916.57.

Seoul pared some of its losses to stand 0.5% off in morning trade.

Australian stocks fell 1.8%, of 73.9 points to 4,031.5.

Crude prices were sharply lower, with New York's main contract - light sweet crude for September delivery - dropping $2.48 to $84.40 a barrel. Brent North Sea crude for September delivery sank $2.48 to $106.89.

Analysts said they expected the markets to recover some of their losses after carnage on Thursday and Friday saw the Dow Jones suffer its biggest fall since 2008.

"We feel there is a reasonable chance for some buying interest as the market begins to realise that it has overreacted to the downside," said IG Markets analyst Ben Potter.

"No one really fully understands the full implications of this credit downgrade, which is why we have seen the market sold off hard. It's a classic case of sell first, ask questions later."