The Competition and Markets Authority (CMA) announced it is launching a preliminary investigation into the deal, before deciding whether to refer it for an in-depth review.

The deal, announced in March, involves a $4 billion (£3.16 billion) investment in Anthropic from Amazon, with Anthropic committing to use Amazon Web Services “as its primary cloud provider for mission-critical workloads, including safety research and future foundation model development”.

The regulator stated it is “considering whether it is or may be the case that Amazon’s partnership with Anthropic has resulted in the creation of a relevant merger situation”.

An Anthropic spokesperson commented: “We are an independent company. Our strategic partnerships and investor relationships do not diminish our corporate governance independence or our freedom to partner with others.

“Amazon does not have a seat on Anthropic’s board, nor does it have any board observer rights. We intend to cooperate with the CMA and provide them with a comprehensive understanding of Amazon’s investment and our commercial collaboration.”

An Amazon spokesperson expressed disappointment: “We’re disappointed that the UK’s CMA has not ended its probe yet. Amazon’s collaboration with Anthropic does not raise any competition concerns or meet the CMA’s own threshold for review.

“The early days of generative AI have largely seen one successful option available for customers. Anthropic has worked hard to become an emerging viable alternative. But, building models is expensive, and companies like Anthropic need access to a substantial amount of capital to train these models.”

Amazon stated that its investment would help increase competition in the emerging sector and that Anthropic is “free to work with any other provider (and indeed has multiple partners)”.