NEW YORK (AP) -- Amazon said Wednesday it is pouring an additional $2.75 billion into Anthropic, bringing its total investment in the artificial intelligence startup to $4 billion.

Amazon will maintain a minority stake in San Francisco-based Anthropic, a rival of ChatGPT maker OpenAI.

"Generative AI is poised to be the most transformational technology of our time, and we believe our strategic collaboration with Anthropic will further improve our customers' experiences, and look forward to what's next," said Swami Sivasubramanian, vice president of data and AI at AWS, Amazon's cloud computing subsidiary.

The Seattle-based tech giant made an initial investment of $1.25 billion in Anthropic in September and indicated then it had plans to invest up to $4 billion.

The two companies are collaborating to develop so-called foundation models, which underpin the generative AI systems that have captured global attention.

Under the deal, Anthropic will use AWS as its "primary" cloud provider and use Amazon's custom chips to build, train and deploy AI models. It will also provide AWS customers, which are mostly businesses, with access to models on an Amazon service called Bedrock. In its announcement Wednesday, Amazon said companies like Delta Air Lines and Siemens are already using Bedrock to access Anthropic's AI models.

The investment is the latest example of how Big Tech companies are spending on artificial intelligence startups amid growing public and business interest in the technology. Earlier this year, U.S. antitrust regulators said they were reviewing these investments.