Amazon and artificial intelligence research firm Anthropic are under investigation for a de facto merger in the UK. The UK's Competition and Markets Authority (CMA) issued a formal notice on August 8 announcing the launch of an investigation into Amazon's $4 billion investment in Anthropic and its exclusivity agreement. The central issue of the investigation is whether Amazon's minority stake and the exclusivity of the two companies constitute an anti-competitive partnership. The current Phase 1 investigation will officially begin on August 9. The CMA said it will announce on October 4 whether it intends to conduct a more in-depth "Phase 2" investigation. Earlier, on March 28, Amazon (AMZN. O) will spend an additional $2.75 billion to support artificial intelligence startup Anthropic, whose Foundation model and chatbot Claude compete with OpenAI and ChatGPT. The two companies announced an initial investment of $1.25 billion in September 23, when they said Amazon would invest up to $4 billion. Anthropic previously launched its latest artificial intelligence model, Claude 3, which the company says is the fastest and most powerful artificial intelligence model to date.