OpenAI was founded in 2015 with the aim of building an artificial general intelligence (AGI) - generally taken to mean AI that can perform any task a human being is capable of. In 2019, the firm announced a new "capped profit" structure allowing it to raise money. Microsoft made an initial 1bn investment into OpenAI shortly thereafter - increasing this to a multi-year, multi-billion dollar partnership in 2023. The lawsuit also accuses boss Sam Altman - a named defendant in the lawsuit - of "rampant self-dealing". Mr Musk's initial legal action filed in March argued the agreement had transformed it into "a closed-source de facto subsidiary" of the PC giant.

Microsoft on Monday announced a new multiyear, multibillion-dollar investment with ChatGPT-maker OpenAI. Microsoft declined to provide a specific dollar amount, but Semafor reported earlier this month that Microsoft was in talks to invest as much as $10 billion. The deal marks the third phase of the partnership between the two companies, following Microsoft's previous investments in 2019 and 2021. Microsoft said the renewed partnership will accelerate breakthroughs in AI and help both companies commercialize advanced technologies in the future. "We formed our partnership with OpenAI around a shared ambition to responsibly advance cutting-edge AI research and democratize AI as a new technology platform," Microsoft CEO Satya Nadella said in a blog post.