By Foo Yun Chee BRUSSELS (Reuters) – Europes top court will rule on Thursday whether MasterCards cross-border card fees, a lucrative revenue source for the financial industry and the subject of a decade-long battle with EU regulators, are anti-competitive. Regulators on both sides of the Atlantic have cracked down on so-called payment card interchange fees, saying they are too high and cost consumers and retailers billions of euros a year. …