Nvidia-backed AI company Coreweave has signed an additional agreement with OpenAI under which the ChatGPT maker has committed to pay Coreweave up to $4 billion through April 2029, a regulatory filing showed on Thursday.

The two have previously teamed up, with OpenAI signing an $11.9bn deal with CoreWeave to use its compute capacity. That deal was not included in CoreWeave's remaining performance obligation (RPO) number, which currently stands at $25.9 billion. It is unclear if the latest $4 billion deal was included.

CoreWeave Inc. has secured a deal worth as much as $4 billion to provide additional cloud computing capacity to artificial intelligence leader OpenAI, expanding a tie-up between the two firms.

OpenAI CEO Sam Altman became a household name after the release of OpenAI's groundbreaking AI model, ChatGPT.

CoreWeave executives had said on a post-earnings call on Wednesday that they had signed an expansion deal without naming the company. They also added CoreWeave had signed on a new hyperscaler as a client,