Stocks in Asia were mixed on Wednesday amid fresh concerns over the outlook for the global economy.

Mainland Chinese stocks were largely unchanged on the day, with the Shanghai composite rising fractionally to 3,241.93 and the Shenzhen component was mostly flat at 10,435.08. The Shenzhen composite declined 0.209 percent to 1,779.28.

The Hang Seng index in Hong Kong declined 0.15 percent in its final hour of trading, as Hong Kong-listed shares of Chinese Construction Bank fell more than 1 percent.

The broad MSCI Asia ex-Japan index rose 0.13 percent to 544.31, as of 3:33 p.m. HK/SIN.

In Japan, the Nikkei 225 declined 0.53 percent to close at 21,687.57 despite shares of index heavyweights Fast Retailing and Softbank Group seeing gains. The Topix index also fell 0.69 percent to finish at 1,607.66.

South Korea's Kospi gained 0.49 percent as chipmaker SK Hynix saw its stock jump 1.03 percent.

Over in Australia, the closed just above the flat line at 6,223.50. The country's central bank deputy governor had said in a speech on Wednesday that it was attempting to ascertain the appropriate policy path amid "conflicting signals" from the labor market, GDP data and business surveys.

"A critical question is which of these is providing the best signal of the global growth impulse? Is it GDP or the labour market? How can we reconcile the difference?" said Reserve Bank of Australia Deputy Governor Guy Debelle, according to a transcript of his speech.

Following that speech, the Australian dollar changed hands at $0.7146 after touching an earlier low of $0.7107.

Meanwhile, shares of Crown Resorts fell 9.11 percent after Wynn Resorts terminated discussions with the Australian gaming firm after the deal talks were leaked.