Aug 11 (Reuters) -

Billionaire Elon Musk said on Monday his artificial

intelligence startup xAI would take legal action against Apple ( AAPL )

, accusing the iPhone maker of breaching antitrust

regulations in managing the App Store rankings.

"Apple ( AAPL ) is behaving in a manner that makes it impossible for

any AI company besides OpenAI to reach #1 in the App Store,

which is an unequivocal antitrust violation. xAI will take

immediate legal action," Musk said in a post on his social media

platform X.

Musk did not provide evidence to support his claim.

Apple ( AAPL ), OpenAI, and xAI did not immediately respond to Reuters'

requests for comment.

ChatGPT currently holds the top spot in the App Store's

"Top Free Apps" section for iPhones in the U.S., while xAI's

Grok ranks fifth and Google's Gemini chatbot sits at 57th.

ChatGPT also leads the rankings on the Google Play

Store, according to Sensor Tower data.

Apple ( AAPL ) has a partnership with OpenAI that integrates

ChatGPT into iPhones, iPads and Macs.

"Hey @Apple App Store, why do you refuse to put either X or

Grok in your 'Must Have' section when X is the #1 news app in

the world and Grok is #5 among all apps? Are you playing

politics?," Musk said in an earlier post Monday.

Musk's comments come as regulators and rivals intensify

scrutiny of Apple's ( AAPL ) control over its App Store.

In April, a U.S. judge

ruled

that Apple ( AAPL ) violated a court order requiring it to allow

greater competition in its App Store and referred the company to

federal prosecutors for a criminal contempt investigation, in a

case brought by 'Fortnite' maker Epic Games.

Apple ( AAPL ) was handed a 500 million euro ($587 million)

fine

by the EU antitrust enforcer in April, saying its technical

and commercial restrictions prevented app developers from

steering users to cheaper deals outside the App Store in breach

of the Digital Markets Act.