BRUSSELS, July 17 (Reuters) - Europe's second-top court on Wednesday dismissed TikTok owner ByteDance's challenge against its designation as a gatekeeper under landmark EU tech rules, in a boost for EU antitrust regulators.

Companies labelled as gatekeepers under the Digital Markets Act (DMA) are subject to a list of dos and don'ts to ensure a level playing field for rivals and more choices for consumers.

"The General Court dismisses the action brought by Bytedance (TikTok) against the decision of the Commission designating it as a gatekeeper," the Luxembourg-based tribunal said.

The case is T-1077/23 Bytedance v Commission. (Reporting by Foo Yun Chee; editing by Philip Blenkinsop)