Microsoft nears deal to buy Yammer: source Sun Jun 17, 2012 4:51pm EDT (Reuters) - Microsoft Corp is close to buying business software company Yammer Inc for more than $1 billion, according to a source familiar with the details. Microsoft's interest in Yammer, known for its social networking functions, could allow the software giant to beef up its offerings for corporations. A Microsoft spokesman declined to comment. A representative from Yammer did not immediately respond to a request for comment. Backed by PayPal co-founder and Facebook investor Peter Thiel, Yammer said it counts more than 80 percent of Fortune 500 companies as clients. It raised more than $140 million in venture capital funding. Bloomberg, which first reported the deal, said the announcement about the transaction was expected at the end of June. Reporting By Jennifer Saba; Editing by Marguerita Choy