• Asia-Pacific stocks were mixed on Wednesday.
• The Caixin/Markit manufacturing Purchasing Managers' Index for August came in at 49.2 on Wednesday, below the 50 mark that separates expansion from contraction.
• Australia's gross domestic product rose 0.7% in the June quarter, above expectations for a 0.5% increase, according to Reuters.

SINGAPORE — Shares in Asia-Pacific were mixed on Wednesday, as a private survey showed shrinking Chinese factory activity in August.

Mainland Chinese stocks closed mixed as the Shanghai composite advanced 0.65% to 3,567.10 while the Shenzhen component dipped 0.1% to 14,314.09. Hong Kong's Hang Seng index edged 0.45% higher, as of its final hour of trading.

The Caixin/Markit manufacturing Purchasing Managers' Index for August came in at 49.2 on Wednesday, below the 50 mark that separates expansion from contraction.

Deutsche Bank International Private Bank's Tuan Huynh said the August reading was not unexpected, adding that the company has lowered its growth forecast for Chinese GDP this year to 8.2% from 8.7%.

"We have seen some weakness in the previous weeks and months already," Huynh, chief investment officer for Europe and Asia-Pacific at the firm, told CNBC's "Street Signs Asia" on Wednesday. "Overall I think China is still here moving ahead and also moving in the right direction."

The Wednesday private survey release came after the official manufacturing PMI released Tuesday showed slowing Chinese factory activity growth in August, coming in at 50.1 against July's reading of 50.4.

PMI readings above 50 represent expansion, while those below that level signal contraction. PMI readings are sequential and represent month-on-month expansion or contractions.

Elsewhere in Japan, the Nikkei 225 jumped 1.29% to close at 28,451.02 while the Topix index advanced 1.02% to finish the trading day at 1,980.79. Meanwhile, South Korea's Kospi climbed 0.24% to close at 3,207.02.

Australian stocks slipped as the S&P/ASX 200 closed 0.1% lower at 7,527.10. Australia's gross domestic product rose 0.7% in the June quarter, according to data released by the country's statistics bureau. That was above expectations for a 0.5% increase, according to Reuters.

MSCI's broadest index of Asia-Pacific shares outside Japan traded 0.18% higher.

Overnight stateside, the S&P 500 declined 0.13% to 4,522.68 while the Dow Jones Industrial Average shed 39.11 points to 35,360.73. The Nasdaq Composite dipped fractionally to about 15,259.24.

Currencies and oil

The U.S. dollar index, which tracks the greenback against a basket of its peers, was at 92.711 following a recent bounce from around 92.4.

The Japanese yen traded at 110.27 per dollar, weaker than levels below 109.8 seen against the greenback earlier in the week. The Australian dollar changed hands at $0.7338 after climbing from below $0.73 yesterday.

Oil prices were higher in the afternoon of Asia trading hours, with international benchmark Brent crude futures rising 0.91% to $72.28 per barrel. U.S. crude futures gained 0.91% to $69.12 per barrel.

Correction: This article was updated to reflect that China's official manufacturing PMI data was released on Tuesday.