Elon Musk has accused Apple Inc. of favoring OpenAI in its App Store rankings, alleging that the iPhone maker makes it difficult for other developers to reach the top positions.

In a pinned post on his X account, Musk questioned whether Apple is "playing politics" by not highlighting his products.

The remarks come as ChatGPT, developed by OpenAI, remains the most-downloaded free iPhone app in the United States, with Musk’s Grok positioned at number five.

Apple has integrated OpenAI’s artificial intelligence features into its latest iPhones.

Musk, founder of xAI Holdings, which includes the Grok AI team and the X social network, stated that his company will pursue legal action, describing Apple’s practices as a potential antitrust issue.

Representatives for Apple and OpenAI did not immediately provide comment.

The dispute adds to a history of tension between Musk and OpenAI Chief Executive Sam Altman, who co-founded the AI company with Musk before their split over strategic disagreements.

Altman responded to the allegations by referencing Musk’s management of the X platform and suggesting it is used to serve Musk’s personal interests.

He added that OpenAI would continue to focus on developing its products.

The confrontation follows Musk’s earlier public clash with U.S. President Donald Trump in June, during which both men exchanged critical remarks on their respective social media platforms.