EU court adviser rejects Mastercard's appeal on card fees

"I propose that the court should dismiss the main appeal and the cross appeals," Advocate General Paolo Mengozzi said in his opinion.

Judges at the Luxembourg-based European Union Court of Justice, who follow the advisers' recommendations in the majority of cases, will rule in the coming months.

The European Commission had said that MasterCard's cross-border multilateral interchange fee, levied on retailers' credit and debit card transactions, violated EU antitrust rules and had to be changed.

(Reporting By Foo Yun Chee; editing by John O'Donnell)