OpenAI is planning to launch its shares on the US stock market, hot on the heels of rival AI giant Anthropic as the industry’s race to go public enters full swing.

The company behind the chatbot ChatGPT announced that it had filed paperwork with the US Securities and Exchange Commission for an expected initial public offering (IPO).

OpenAI said in a blog post that the filing was “confidential” but it was choosing to announce it because it expects the news to “leak”.

“We have not decided on timing yet; it may be a while because there are things we want to do that are likely easier as a private company,” the company said.

“But it’s a complicated set of tradeoffs and this gives us the option to go public sooner if that ends up being best.”

The filing involves submitting a prospectus to register interest in an IPO, which if it went ahead would see the company’s shares launched on the public market.

It is thought that it could be one of the biggest debuts on Wall Street, with OpenAI’s most recent valuation coming in at more than 850 billion US dollars (£636 billion).

The company, headed by chief executive Sam Altman, says it is generating around two billion dollars (£1.5 billion) in revenues each month.

It also recently revealed it was building an “AI superapp” which it said will bring together ChatGPT, its coding tool Codex, and browsing capabilities.

It comes a week after Anthropic, which makes the chatbot Claude, revealed it had also submitted the paperwork to fire the starting gun on a potential listing.

Anthropic is valued at nearly 1.0 trillion US dollars (£750 billion) following its meteoric rise from a research laboratory founded five years ago.

At the same time, Google’s parent firm Alphabet said it was looking to raise 80 billion US dollars (£59.9 billion) in equity to fund its AI infrastructure investments – its first stock offering in more than 20 years and one of the largest ever equity raisings.

Elon Musk’s rocket and AI company SpaceX is also preparing to list on the Nasdaq stock exchange in the US.

The planned listings increase the pace of activity in the fast-growing industry as firms look to capitalise on the boom in investor demand for AI.