Vodafone Group Plc (NASDAQ:VOD) stock is trading lower Wednesday as the UK antitrust regulator, Competition and Markets Authority (CMA), began its Phase 1 investigation into Vodafone UK’s joint venture agreement with CK Hutchison Holdings Ltd (OTC:CKHUY) (OTC:CKHUF) Three UK. The deal combined the companies’ telecommunications operations under one network provider. The CMA now has up to 40 working days to evaluate the deal. It aims to analyze the proposed deal’s potential impact on competition for consumers and businesses. Post-merger Vodafone will own 51% of the combined business, and CKHGT w…