The UK antitrust authority said the purchase would hurt competition in cloud gaming.

It’s part ofgrowing concerns that big tech mergers could affect usersworldwide.

The UK body said it was not concerned that the deal would distort competition in the console gaming market.

The exterior of a Microsoft store in London, UK.

Jeremy Moeller / Getty Images

Microsoft and Activision Blizzard struck out at the decision and said they would appeal.

Activision Blizzard makes hit games likeCall of Duty,World of Warcraft, andCandy Crush.

Global innovators large and small will take note thatdespite all its rhetoricthe UK is closed for business."

Someone playing online games at a computer desk in the middle of a living space.

PhotoAttractive / Getty Images

PhotoAttractive / Getty Images

The antitrust move could also reverberate beyond gaming, Hsu said.