European Union (EU) regulators on Wednesday ordered mail carriers German's Deutsche Post and Belgium's Bpost to repay state subsidies, saying the aids broke EU anti-trust rules.

Deutsche Post, Europe's largest mail carrier, will have to repay between 500 million euros (about 647 million U.S. dollars) and 1 billion euros to German authorities, the European Commission said in a statement on its website.

"The aid placed Deutsche Post in a better position than its competitors," the statement said.

The Commission also ordered Belgium's Bpost to pay back 417 million euros as the EU regulators found the postal firm had been over-compensated for services provided between 1992 and 2010.

The decisions resulted from an investigation over whether state subsidies distorted the postal service market in Belgium, France, Germany and Greece, according to the statement.

"Our ultimate aim is to prevent distortion of competition which would hinder citizens and businesses from enjoying the benefits of full market opening," the statement quoted EU's Competition Commissioner Joaquin Almunia as saying.

Full liberalization of the postal market across the EU would be complete by the end of this year, with 11 nations yet to achieve the goal, Almunia added. (1 euro=1.29 U.S. dollars)