Since last September, the tech giant has pumped $8 billion into the artificial intelligence start-up, a sign of intense competition in developing tools that are reshaping the tech sector.

Amazon.com pumped another $4 billion into OpenAI competitor Anthropic, as the e-commerce giant goes up against Big Tech rivals in a race to capitalize on generative artificial intelligence technology.

Amazon is investing the additional $4-billion in Anthropic as part of an expanded alliance that includes working together on "Trainium" hardware to optimise machine learning, according to the companies.