The ChatGPT maker is seeking up to $30 billion ahead of a possible 2027 IPO.
OpenAI has lowered its target valuation for a new funding round to $1.25 trillion from $1.4 trillion after some investors resisted the higher figure, according to reports.
The revised target is still about 50 per cent above the company's current valuation of $852 billion. OpenAI aims to raise up to $30 billion as a bridge to a possible IPO in the first half of 2027.
Investor demand is said to be weaker than in earlier rounds, amid a sell-off in US tech stocks and questions over returns on AI spending. Investors have until October 30 to commit.
OpenAI raised a record $122 billion in March. Chief executive Sam Altman has ruled out a listing this year.
