Elon Musk said late Monday that his artificial-intelligence startup xAI will initiate legal proceedings against Apple, accusing the iPhone maker of violating antitrust laws by favoring OpenAI’s ChatGPT in its App Store rankings. Musk claims Apple’s policies make it “impossible” for any rival chatbot to reach the platform’s top spot. As of Monday, ChatGPT held the No. 1 position among free iOS apps in the United States, while xAI’s Grok ranked fifth, according to data cited by Reuters. Apple integrated ChatGPT into iPhones, iPads and Macs under a 2024 partnership; the company has so far declined to comment on the accusation. OpenAI Chief Executive Officer Sam Altman called Musk’s allegation “remarkable,” noting that other developers have briefly topped Apple’s charts. China-based DeepSeek AI, for example, reached No. 1 in January, undercutting Musk’s contention that the ranking is unreachable for competitors. The dispute intensifies scrutiny of Apple’s control over its storefront. In April, European regulators fined the company €500 million for restricting developers’ ability to steer users to cheaper alternatives, while a U.S. judge referred Apple to prosecutors for allegedly flouting a separate App Store injunction. Apple’s shares slipped about 0.6 percent in early Tuesday pre-market trading following Musk’s remarks. xAI has not detailed when it will file its suit, and both companies have yet to disclose further legal steps.