Summary Summary Companies UK regulator that blocked Microsoft-Activision deal to scrutinize tie-up Previous consolidation attempt by Hutchison, O2 was not allowed Companies say deal will deliver 5G network Britain needs LONDON, June 15 (Reuters) - It has taken months of tortuous negotiations for Vodafone (VOD.L) and CK Hutchison (0001.HK) to agree a deal to create Britain's biggest mobile operator, but from a regulatory standpoint the hard work is only just beginning. The $19 billion tie-up will be scrutinised by Britain's Competition and Markets Authority, the antitrust regulator which made global headlines in April when it blocked Microsoft's $69 billion acquisition...