The logo of U.S. clothing manufacturer Guess is seen outside a store in Vienna, Austria, June 4, 2016. REUTERS/Leonhard Foeger

BRUSSELS (Reuters) - The European Commission said on Tuesday it would open a formal investigation into clothing group Guess GES.N, saying it suspected the company of banning retailers from selling its products across the EU's national borders.

The Commission said that if confirmed, such practices were against EU law guaranteeing the free movement of goods across the single market.

“We are going to investigate Guess’s practices further to ensure that it is playing by the rules and not preventing consumers from buying products across borders,” Competition Commissioner Margrethe Vestager said.