European shares were boosted by better-than-expected flash PMI (purchasing managers' index) data for the euro zone. Euro zone PMI rose to an 18-month high in July, according to data out on Wednesday. The number came in at 50.4 — above the 50-mark that divides expanding activity from contraction — compared to 48.7 in June. The euro traded higher after the news, hitting a one-month high.
"Encouraging news," Howard Archer, an economist at IHS Global Insight, said in a note. "With the euro zone purchasing managers surveys supportive to the view that the euro zone has finally stopped contracting and could very well eke out marginal growth over the second half of the year."
However, shares in Asia declined after HSBC's flash estimate of Chinese PMI fell to an 11-month low of 47.7 in July. The data fueled fears of further slowdown in the world's second-largest economy.
(Read more: China's factory activity plunges to 11-month low)
Dell gained after founder Michael Dell and Silver Lake raised their bid to $13.75 a share in cash for the PC maker. The company said the special shareholder meeting will be delayed to Aug. 2 while it considers the new offer.
Also among techs, Google will make a product announcement at 12 p.m. ET, with speculation over a new Android operating system and tablet.
Weekly mortgage rates dropped last week for the first time in 2-1/2 months following reassuring comments from Fed Chairman Ben Bernanke, but demand for home loans still declined, according to the Mortgage Bankers Association.
New home sales for June is expected to be released at 10 am ET. Sales are forecast to rise to an annual rate of 482,000 last month from 476,000 in May, according to a Reuters survey.
The Treasury is scheduled to auction $35 billion in 5-year notes with the results available at 1 pm ET.
Meanwhile, President Barack Obama will travel to Galesburg, Illinois and Warrensburg, Missouri, where he is expected to speak on the economy.