BRUSSELS (AP) — The European Union is opening an antitrust probe into U.S. online shopping giant Amazon to see whether it uses data from independent retailers to gain an edge in the market.

EU antitrust Commissioner Margrethe Vestager said Wednesday she is taking a "very close look at Amazon's business practices and its dual role as marketplace and retailer, to assess its compliance with EU competition rules."

The EU opened a preliminary probe into the issue last year, and Vestager said Wednesday that it has shown that "Amazon appears to use competitively sensitive information - about marketplace sellers, their products and transactions on the marketplace."

Using the information could give it a competitive edge. Vestager said: "We need to ensure that large online platforms don't eliminate these benefits through anti-competitive behavior."