Apple Inc. blocked an antitrust lawsuit over App Store fees filed by a handful of iPhone users from being expanded to include millions of customers across the US.

A federal judge in Oakland, California, on Tuesday refused to let the case proceed on behalf of users who hold almost 400 million US Apple accounts and have purchased apps and virtual goods from the App Store.

The judge allowed the plaintiffs to revise and refile their request. But if her ruling stands, it will eviscerate a decade-old case that could potentially expose the iPhone maker to billions of dollars in damages.

Plaintiffs "fully expect” the judge to grant class certification in the future, said Mark Rifkin, a lawyer representing the consumers. "While we are disappointed that the court has not yet granted class certification, the court has given us a clear roadmap to follow when we renew the motion.”

Class-action status would give consumers considerable settlement leverage in their challenge to the lucrative App Store business, which analysts say brings in more than US$20bil a year with a profit margin above 75%.

Potential damages for the class would run from US$7-10bil , lawyers for the consumers said at a hearing in November.

Apple is also fighting Epic Games Inc. over App Store fees and facing scrutiny from global regulators examining the tech giant’s power as a gatekeeper to the digital economy.

The consumer case is In re Apple iPhone Antitrust Litigation, 11-cv-06714, U.S. District Court, Northern District of California (Oakland).

 - Bloomberg