* TikTok's challenge made at EU Court of Justice

* ByteDance says it lacks entrenched, durable EU market

position

* Court ruling could reshape EU's Big Tech regulatory

landscape

By Foo Yun Chee

LUXEMBOURG, May 12 (Reuters) - Bytedance's social media

platform TikTok on Tuesday made a last- ditch attempt at

Europe's top court to scrap its designation as a

"gatekeeper"under EU rules, which require it to meet tougher

standards as regulators seek to curb the power of Big Tech.

The case--the first EU Digital Markets Act "gatekeeper"

challenge heard by the EU Court of Justice--could bolster or

weaken Europe's attempt to rein in Big Tech to ensure

competition and more choice for users.

TikTok was designated a "gatekeeper" under DMA in September

2023, joining other companies with more than 45 million monthly

users. These included Alphabet's Google, Meta

Platforms ( META ), Apple ( AAPL ), Amazon ( AMZN ), Microsoft ( MSFT )

and Booking.com.

A lower court tribunal had in 2024 thrown out TikTok's

challenge, saying it met DMA criteria for the gatekeeper

designation.

The DMA sets out an onerous list of requirements aimed at

curbing the power of Big Tech, with infringement fines as high

as 10% of a company's annual turnover.

DOESN'T MEET THE EU'S CRITERIA, TIKTOK SAYS

TikTok argued the tribunal had erred in its ruling that the

company failed all three criteria for gatekeeper status:

significant market impact, acting as a key business gateway to

users, and holding an entrenched market position.

"ByteDance showed not only that its market cap is

overwhelmingly derived from its Asian businesses but also they

had no connection to Europe, face different competitive dynamics

and operate in a distinct regulatory, linguistic and cultural

environment," TikTok's lawyer Bill Batchelor said at Europe's

top court.

He told the panel of 15 judges that 70%-80% of TikTok users

use multiple other platforms in parallel, including Meta

Platform's Facebook and Instagram, Snap and X, and hence were

not locked into TikTok's ecosystem.

"We refer to this as 'multihoming.' That means businesses

can reach the same end users via multiple other platforms,"

Batchelor said.

A European Commission lawyer dismissed TikTok's arguments.

"Lock-in can occur even when some degree of multihoming

exists. For example, there may be specific user groups that

depend on TikTok," Mislav Mataija told the Court.

The Court will rule in the coming months. Meta Platforms ( META ) is

also contesting its gatekeeper designation for Messenger and

Marketplace.

The case is C-627/24 P Bytedance v Commission.