• A private survey showed China's services sector activity growth slowing sharply in January. The Caixin/Markit services Purchasing Managers' Index for January came in at 52, representing its slowest growth pace in nine months.
• Reserve Bank of Australia Governor Philip Lowe said in a Wednesday address that "very significant monetary support will need to be maintained for some time to come."

SINGAPORE — Stocks in Asia-Pacific were mixed on Wednesday as a private survey showed China's services sector activity growth slowing sharply in January.

Mainland Chinese stocks declined on the day, with the Shanghai composite down 0.46% to 3,517.31 while the Shenzhen component slipped 0.668% to 15,233.15. Hong Kong's Hang Seng index nudged 0.2% higher to close at 29,307.46.

The Caixin/Markit services Purchasing Managers' Index for January came in at 52, representing growth at its slowest pace in nine months. That compared against December's reading of 56.3.

Levels above 50 in PMI readings represent expansion while those below that level signify contraction. PMI readings are sequential and show on-month expansion or contraction.

Elsewhere, major markets in Asia-Pacific saw gains.

Japan's Nikkei 225 closed 1% higher at 28,646.50 while the Topix index ended its trading day 1.3% higher at 1,871.09. South Korea's Kospi closed 1.06% higher at 3,129.68.

MSCI's broadest index of Asia-Pacific shares outside Japan rose 0.67%.

In corporate news, Hong Kong-listed shares of Alibaba edged 0.38% higher on Wednesday. It came after the Chinese tech giant reported that its cloud division was profitable for the first time. The e-commerce company is looking to raise up to $5 billion via U.S. dollar-denominated bonds, a person familiar with the matter told CNBC.

Meanwhile, shares of South Korean automaker Kia Motors soared 9.65% on Wednesday. That came following a local media report that the carmaker is set to sign a 4 trillion won (about $3.59 billion) deal with Apple to build electric vehicles, according to Reuters.

Overnight stateside, the Dow Jones Industrial Average soared 475.57 points to close at 30,687.48 — its best daily performance since November. The S&P 500 rose 1.4% to finish its trading day at 3,826.31 while the Nasdaq Composite gained 1.6% to close at 13,612.78.

Currencies and oil

The U.S. dollar index, which tracks the greenback against a basket of its peers, was at 91.092 following its rise from levels below 90.8 earlier this week.

The Japanese yen traded at 105.02 per dollar, still weaker than levels below 104 against the greenback seen last week. The Australian dollar changed hands at $0.761, following an earlier low of $0.7599.

Oil prices were higher in the afternoon of Asia trading hours, with international benchmark Brent crude futures up 0.54% to $57.77 per barrel. U.S. crude futures gained 0.35% to $54.95 per barrel.