EU antitrust regulators are rumoured to announce that they will approve the Activision deal on May 15.
The EU antitrust enforcer is expected to clear the acquisition after Microsoft agreed to licensing deals with cloud streaming rivals including Nvidia, Ukraine's Boosteroid and Japan's Ubitus.
It has an agreement with Nintendo to bring Activision's Call of Duty to its gaming platforms should the acquisition go through. US distributor Valve, owner of the world's largest video game distribution platform, Steam, declined a contract saying it trusts Microsoft.
Japan approved the takeover in March while the US Federal Trade Commission is seeking to block it for now.