LONDON, July 29 (Reuters) - Britain's antitrust regulator said it would investigate Microsoft over whether it misled ‌personal and family customers when marketing subscription ‌plans for its ever-popular Microsoft 365 product, resulting in them overpaying. The ​Competition and Markets Authority said on Wednesday the probe would examine Microsoft's addition of its AI assistant Copilot to Microsoft 365 subscriptions. Personal and family customers were initially ‌offered Copilot at ⁠no extra cost, but some later faced higher-priced subscriptions when renewing. The CMA said while it was supportive of AI adoption across the country, customers always needed clear and timely information. Authorities in Australia and Italy are also investigating Microsoft ​over the information ‌provided to customers when plans renewed, the CMA ​noted.