Microsoft Corp gained EU antitrust approval for its $69 billion acquisition of Activision on Monday, in a significant boost that could prompt Chinese and Korean regulators to follow suit despite a British veto of the deal. The US software giant still faces a battle to clinch a deal. It has until May 24 to appeal a decision by Britain's Competition & Markets Authority (CMA) to block it. A final decision may take months. The US Federal Trade Commission's case against the deal is also pending at the agency.