OpenAI’s corporate restructuring is likely to slip into next year, as the ChatGPT maker negotiates over key terms of its future relationship with Microsoft, complicating plans to raise billions of dollars more in funding.

The $300bn artificial intelligence start-up has been locked in complex discussions with the software giant, its biggest backer, to rewrite an existing commercial contract between the companies that runs until 2030.

A deal would allow OpenAI to complete plans for a restructure which would allow investors to hold equity in the business and unlock a future initial public offering. But multiple people with knowledge of the talks said there is still distance between the two sides on key issues that could push negotiations beyond December 31.

Failure to reach an agreement by that date would allow SoftBank to withhold its $10bn commitment to the company, according to the terms of the Japanese group’s investment. It could also hamper OpenAI’s efforts to raise more capital.