Amazon is investing another $2.75 billion in growing artificial intelligence company Anthropic, TechCrunch reported. With this, it closed a deal it struck last year to back the startup and expand the partnership between the two companies.

Amazon’s total investment in Anthropic is worth $4 billion.

According to sources, Amazon had until the end of the first quarter to decide whether to increase its investment to a maximum of $4 billion, and a few months later – the investment is already in place.

Anthropic’s AI models are one of very few that compete at the highest levels of capability, but are available at enterprise scale for internal deployment or in consumer-facing applications.

OpenAI’s GPT AI chatbots and Google’s Gemini are well known among tech circles, but newcomers like Mistral could very well threaten the AI dominants.

They identify 2021-founded Anthropic as one of OpenAI’s biggest competitors, attracting billions in funding.

Anthropic has relationships with big tech companies like Google, which joined a $450 million funding round in May led by Spark Capital. Google and Amazon Web Services are partners in Anthropic’s cloud computing.