The Asian Development Bank on Tuesday said it expected China, the world's second largest economy, to grow by 6.8 percent this year, down from a previous forecast of 7.2 percent.
In addition to the China PMI data, markets also digest PMI readings from Europe and the September U.S. flash manufacturing PMI at 09:45 a.m. ET.
Chinese President Xi Jinping, visiting the U.S. this week, on Tuesday said China's economy would remain on a "steady course" and reassured the world that China's financial markets will remain stable.
Read MoreChina's Xi defends economy, markets at US address
In the wake of last week's U.S. Federal Reserve decision to keep interest rates at record low levels amid concerns about the global growth outlook, attention was also expected to turn to Fed speakers for further insight into when rates may be raised.
Atlanta Fed President Dennis Lockhart speaks at 12:30 pm ET.
Analysts at Daiwa Capital said in a note that Lockhart is a relatively "centrist" member of the Fed, noting that earlier in the week he suggested a rate hike in the fourth quarter of the year was still on the cards as long as market volatility settles down.
European Central Bank President Mario Draghi speaks before the Committee on Economic and Monetary Affairs (ECON) of the European Parliament in Brussels at 9 a.m. ET.
A sharp fall in the shares of German car maker Volkswagen was also expected to continue to weigh on sentiment as investors assess the fallout of an emissions scandal.
Volkswagen shares, which have slid more than 30 percent in the past two sessions, tumbled a further 3.8 percent in early Wednesday trade in Europe.
Read MoreEarly movers: CTSX, INTC, CSCO, FB, JCP & more
Back in the U.S., Steelcase, Worthington Industries are expected to report earnings, while the U.S. Treasury is expected to sell $35 billion worth of five-year bonds later in the day.