San Francisco, June 26 - Microsoft has acquired business-focused social network Yammer for $1.2 billion.

"The acquisition underscores our commitment to deliver technology that businesses need and people love," said Steve Ballmer, Microsoft's chief executive officer.

"Yammer adds a best-in-class enterprise social networking service to Microsoft's growing portfolio of complementary cloud services," Xinhua quoted him as saying Monday.

Launched in September 2008, Yammer provides private communication within organisations and pre-designated groups.

According to Microsoft, Yammer now has more than five million corporate users, including employees at 85 percent of the Fortune 500 companies. (IANS)