VIENNA - Austria's competition authority has initiated an investigation into whether Amazon is exploiting its market dominance in relation with other retailers that use its website as a marketplace, it said on Thursday.

The probe follows a similar move by German authorities, which announced an investigation in November.

European regulators have been taking a tough line on U.S. tech giants like Google and Facebook, while the European Commission is also looking into Amazon's dual role as retailer and marketplace.

The Austrian regulator said it would examine terms and conditions under which the U.S. online giant grants Austrian vendors access to its marketplace.

"There is a suspicion that Amazon puts other retailers on a disadvantage on its marketplace, thereby trying to favour its own offerings," it said in a statement.

Amazon did not immediately have a comment.

Austrian retailers had filed a complaint against the U.S. firm over its dual role as a retailer and a marketplace with the authority in December.

They said Amazon could in theory see the prices of the listed retailers on its platform, undercut their prices and attract all that business in the long run.

Nearly every Austrian online shopper has made at least one purchase on Amazon, according to the Austrian Retail Association.

(Reporting by Kirsti Knolle; Editing by Edmund Blair) ((kirsti.knolle@thomsonreuters.com; +43 1 53112 255; Reuters Messaging: kirsti.knolle.thomsonreuters.com@reuters.net www.reuters.com))