Apple trial threatens to reveal App Store’s commission bounty

Apple Inc.’s App Store has long been touted as a growth engine. Now, the world’s most valuable company is fighting in U.S. court to not reveal in public just how lucrative it is.

In a trial scheduled to start Monday, Epic Games Inc. is alleging that the iPhone maker’s 30% commission on app sales is a violation of antitrust law, cheating developers and consumers. Epic’s long-odds gambit to gain free access to the App Store, which has garnered support from mom-and-pop developers and giants like Microsoft Corp., comes amid increasing global regulatory scrutiny of Apple’s domination of software on its ubiquitous phones. On Friday, the European Union issued a warning over the App store, saying it thinks Apple abused its power.