(Reuters) - Asian stocks edged up on Wednesday after upbeat U.S. economic growth data calmed investor anxiety over a deteriorating global outlook, while the Australian dollar languished near four-year lows against the dollar.

Oil prices were also under pressure as major oil producing nations failed to agree on curbs to output ahead of an OPEC meeting on Thursday.

The U.S. government upgraded its reading on third quarter gross domestic product to 3.9 percent on Tuesday from 3.5 percent reported last month. Economists polled by Reuters had expected growth would be cut to 3.3 percent.

"The gap between actual and estimated third quarter GDP was a big one, but what is of increasing import is the gap between theeconomy of the U.S. and the rest of the world especially Europe and Japan," Jasper Lawler, analyst at CMC Markets, said in a note.

MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS gained 0.3 percent. Australian shares .AXJO rose 0.9 percent after

Mainland Chinese shares hit fresh three-year highs, helped by last Friday's rate cuts from the People's Bank of China while Tokyo's Nikkei .N225 retreated 0.1 percent, weighed by the yen's bounce.

The 10-year U.S. Treasuries yield dropped to one-month low of 2.252 percent US10YT=RR, as strong auction results, month-end buying and an unexpected drop in U.S. consumer confidence offset the encouraging GDP news.

That also helped the dollar put some distance from a seven-year high against the yen .

The greenback was down 0.1 percent at 117.82 yen JPY=, pulling further away from a seven-year high of 118.98 reached the previous week. The euro was little changed at $1.2477EUR=.

In contrast, the Australian dollar hovered near a four-year low of $0.8514 AUD=D4. The Aussie has been under pressure amid the recent tumble in the price of iron ore, Australia's key export commodity.

"The AUD sits squarely at the bottom of the G10 pack in the past 24 hours and heading into the NY close, with a fresh slide in iron ore prices, now to below $70 for the first time since June 2009, adding pressure," said Ray Attrill, global co-head of FX strategy at NationalAustralia Bank.

Crude oil extended losses after a meeting of Saudi Arabia and three other nations ahead of Thursday's closely-watched OPEC summit ended with no deal to curb crude output. [O/R]

U.S. crude CLc1 was down 24 cents at $73.85 a barrel, near a four-year low of $73.25 hit a little more than a week ago.