The United Kingdom’s antitrust regulator on Friday approved Microsoft’s $69 billion acquisition of the Santa Monica, California-based video game-maker Activision Blizzard, setting the stage for the deal’s completion after 21 months of regulatory wrangling around the globe.

The pending completion of the deal serves as monumental achievement for Microsoft president and vice chair Brad Smith, a former chief legal officer of the Redmond, Washington-based company who shepherded the deal through a maze of obstacles, an effort that at times seemed doomed to failure.