LONDON — E-commerce giant Amazon’s multibillion-dollar investment in the U.S. artificial intelligence firm Anthropic is formally being investigated by a U.K. competition regulator.

The Competition and Markets Authority said Thursday that it has begun a “Phase 1” investigation into Amazon’s investment and partnership with Anthropic to assess whether the deal has resulted in a relevant merger situation that may harm competition in the U.K.

Following initial scrutiny into the Amazon-Anthropic partnership, the CMA now has “sufficient information” in relation to the tie-up to begin a formal probe, the regulator said in a notice on its website.

The CMA now has up to 40 working days to decide whether the transaction could harm competition and should therefore be scrutinized further in an in-depth “Phase 2” investigation.

Amazon and Anthropic were not immediately available for comment when contacted by CNBC.

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