Elon Musk reportedly called for lawmakers in two US states to force Chat-GPT maker OpenAI to auction large stakes in its business, the latest development in a long-running row between the two parties.

Financial Times reported it viewed a letter from a lawyer representing Musk calling on attorney-generals in California and Delaware to force an auction of OpenAI, stating he was arguing the case on behalf of big AI investors who want an open and competitive bidding process for a stake in the business.

Musk was one of the co-founders of OpenAI along with current CEO Sam Altman and nine other people.

However, the X and Tesla-owner left OpenAI’s board in 2018 due to clashes with Altman and has since launched several lawsuits against the company.

Musk has taken particular issue with OpenAI’s plans to restructure to create a for-profit entity separate from its non-profit business.

It currently has a for-profit arm which raised $13 billion from investors. However, the unit is owned by its non-profit entity, in addition to the company’s employees and investors.

A corporate restructure would make the two units independent from each other, to enable it to raise even more cash.

However, Musk is arguing for the company to hold an auction to determine a fair market value for OpenAI’s charitable assets, in a bid to protect the public’s interests.

Responding to his request, an OpenAI representative told FT it has no plans to hold an auction, adding Musk and his camp simply “want more chaos”.

The news caps a difficult few days for OpenAI boss Altman, who was hit with a lawsuit from his sister over allegations of abuse.

Altman released a statement denying any wrongdoing.