Call of Duty: Warzone
  • Activision Blizzard shares sank Wednesday after the UK blocked its pending buyout by Microsoft. 
  • A UK regulator said the $69 billion deal would cause "harm" to competition in cloud gaming in the country. 
  • Microsoft said it will appeal the regulator's decision. 

Activision Blizzard sharply dropped Wednesday after the "Call of Duty" publisher's pending buyout by Microsoft was rejected by a UK regulator on the grounds it would hurt competition in cloud gaming.  

Activision shares fell about 10% at the open to $79.30. The stock dropped below $80 a share for the first time in a month after the $69 billion merger deal was blocked.