ASX falls 1%
Australia's benchmark S&P ASX 200 index widened losses to settle at a near one-week low, chalking up a third straight decline this week, as weakness in commodity-related sectors weighed on the resource-heavy bourse.
As iron ore fell below $70 a tonne, big miners languished; Fortescue Metals led declines with a nearly 9 percent slump, while Rio Tinto and BHP Billiton finished 3.3 and 2.8 percent lower, respectively.
Oz Minerals and PanAust saw sharp losses of 12 and 10 percent each after benchmark three-month copper on the London Metal Exchange hit its weakest since July 2009. As the price of copper sank, the latter announced late Wednesday that it is reducing 5 percent of its workforce, mostly employed at its copper mine in Laos.
There were a few bright spots, however. Santos outperformed fellow energy producers to rise 2 percent after its chief executive signaled that asset sales are being considered amid slumping oil prices. Whitehaven Coal got a boost from news that it achieved record coal sales in the three months to December 31. Shares of the miner advanced 1.3 percent.
Meanwhile, the fall in copper prices also took a hit on the Australian dollar, which fell nearly 1 percent to a near one-week low, fetching $0.8095 against the U.S. dollar late Wednesday.
Read MoreAussie dollar to keep falling - but how much further?
Mainland indices down
China's Shanghai Composite index erased gains to turn lower in the afternoon session amid the depressed mood in Asian markets, while the blue-chip CSI300 index ended the day 0.3 percent lower.
Among losers, energy plays struggled on the back of the prolonged oil rout; PetroChina and China Oilfield Services closed down nearly 3 percent each.
Fortunately, the banking sector capped losses on the bourse, with Bank of China rising 3.6 percent, Bank of Communication and China Construction Bank piling on nearly 3 percent each while China Merchants Bank tacked on 1.9 percent.
In Hong Kong, the key Hang Seng index also reversed gains to inch down 0.4 percent following an annual policy speech by the city's chief executive CY Leung, who addressed issues on political reform and housing.
Hence, property plays were in focus; Wheelock and Sun Hung Kai Properties were down 2 and 1.5 percent each while Cheung Kong Holdings lost 0.6 percent.
Yashili International, a unit of China Mengniu Dairy, recouped losses to climb up 0.9 percent on Wednesday despite warning that its 2014 annual profit was expected to fall about 40 percent. Shares of China Mengniu Dairy pulled back 1 percent.