Elon Musk has formed an X.AI artificial intelligence corporation based in the US state of Nevada, according to business documents that surfaced on Friday.

Musk, who is already the boss of Twitter and Tesla, was listed as director of X.AI Corporation founded on March 9, according to a state business filing.

Musk recently merged Twitter with a newly created "X" shell company, keeping the brand name for the platform but not the business.

Musk's founding of what appears to be a rival to ChatGPT-maker OpenAI came despite recently calling for an overall pause in developing artificial intelligence.

Musk has bought thousands of powerful, costly computing processors and hired engineering talent as part of an AI project at Twitter, according to an Insider report.

Meanwhile, Musk has slashed staff at Twitter as part of dramatic cost cutting since his US$44 billion takeover of the San Francisco firm late last year.

The founding date of X.AI was several weeks before Musk joined experts in signing an open letter calling for a hiatus in the development of AI.

The open letter, published on the website of the Musk-funded Future of Life Institute, urged a six-month pause in development of powerful AI systems.

The billionaire Tesla chief and other luminaries wrote that "AI systems with human-competitive intelligence can pose profound risks to society and humanity."

The signatories, who included academics and tech titans like Apple cofounder Steve Wozniak, argued that the pause should be used to bolster regulation and ensure the systems were safe.

Big tech companies like Google, Meta and Microsoft have spent years working on AI systems -- previously known as machine learning or big data -- to help with translations, search and targeted advertising. (AFP)