EU antitrust regulators launched proceedings on Thursday to ensure that Apple complies with landmark rules requiring it to open up its closed ecosystem to rivals or risk a possible hefty fine.

Many of the law’s provisions apply not at the company level, but rather only to specific products that the EU designates as core platform services. Apple’s iOS, App Store and Safari received that designation last September,

The European Union antitrust regulators launched proceedings on Thursday to ensure that Apple complies with landmark rules requiring it to open up its closed ecosystem to rivals or risk a possible hefty fine.

Britain won on Thursday its fight against an EU order to recover millions of euros from the London Stock Exchange , broadcaster ITV and other multinationals, in a setback to EU regulators' crackdown on certain tax schemes.

In an effort to quell monopoly concerns in the EU, Google reportedly offered to sell its AdX advertising marketplace. Sources told Reuters that European publishers rejected Google's offer, arguing that the company would have to divest more in order to dismantle the conflicts of interest in its online advertising operations.

Europe's second-top court on Wednesday backed Alphabet unit Google's challenge against a 1.49 billion euros ($1.66 billion) antitrust fine imposed five years ago for hindering rivals in online search advertising.