Nvidia is reportedly in talks to guarantee about $250bn of financing for OpenAI, a backstop that would let the ChatGPT maker fund a vast new data centre without the investment-grade credit rating such borrowing normally demands. The arrangement was described by the Wall Street Journal on July 26, and neither company has confirmed it.

The guarantee would not involve Nvidia handing over cash. It is a promise to cover the obligations if OpenAI or the project falls short, the sort of vendor support that has already drawn scrutiny as circular financing spreads through the AI economy. For a chipmaker that has spent the year making AI equity bets at a pace few rivals can match, it is another way of underwriting demand for its own hardware.

The money is tied to a 10-gigawatt campus in southern Ohio, developed by an energy subsidiary of SoftBank and leased by OpenAI, according to the Journal.

The $250bn would cover the data-centre lease and the construction debt behind it, with a further sum of up to $350bn discussed separately to fund chip purchases, potentially pushing the total project cost beyond $500bn.

The two tranches are being negotiated on different tracks, and none of the terms, including the fee Nvidia would charge for the guarantee, has been made public.