Darin Williams is new chief at Facebook SEA

Williams takes over from Stephen Dolan, who will be moving into a new role at Facebook. A spokesperson at Facebook said Dolan is expected to focus on the Japan and Korea markets.

Both Williams and Dolan will report directly to Erik Johnson, Facebook’s APAC vice-president.

In his new role, Williams will oversee sales support functions across markets like Singapore, Malaysia, Indonesia, Thailand and Philippines. His LinkedIn profile states that he joined Facebook in December 2012. Williams was most recently managing director of Nielsen Vietnam between 2009 and 2012. Prior to that he was executive director for Nielsen Korea and has also spent close to 10 years with Nielsen Japan.

Johnson said Williams will partner with advertisers and agencies in Southeast Asia to extend their brand presence online.

According to Dolan's LinkedIn profile, he moved from Microsoft to Facebook more than two years ago.