The UK’s antitrust regulator is initiating an investigation into Amazon’s relationship with AI startup Anthropic following a $4 billion investment by Amazon into the company. The investigation will determine if this investment constitutes a merger under current regulations set by the Competition and Markets Authority (CMA) and if it will impact competition in the country. Amazon has stated that the investment does not give them a majority stake in Anthropic, and both companies deny that the investment implies a merger. This investigation is part of a larger effort by UK regulators to address “quasi-mergers,” where larger companies influence startups through investments or talent acquisition. The CMA is also planning to investigate Google’s significant investments in Anthropic, in addition to looking into Microsoft’s partnership with OpenAI and hiring of Inflection AI’s core team.