The deal could be valued at more than $1 billion, Bloomberg reports.
In February, Yammer raised $85 million in a venture round that valued the company at a post-money valuation of more than $600 million, according to people familiar with the matter. An acquisition at $1 billion or more would be a quick jump in value and would make a quick return even for those who invested just in the most recent round.
That large $85 million round, CEO David Sacks said at the time, in some ways takes away the need for an IPO. Yammer raised the round in part to rapidly expand as demand for its products grew and it sought to compete with others such as Salesforce.com, which launched a similar product Chatter, as well as others such as recently public Jive Software.
Yammer has raised about $142 million from DFJ Growth, Social+Capital Partnership, Meritech Capital Partners, Capricorn Investment Group LLC, the investment arm of Jeff Skoll, Khosla Ventures, Crunchfund, Charles River Ventures, Emergence Capital, Founders Fund and U.S. Venture Partners.
Yammer has established itself as one of the major companies in the social enterprise space, focusing on a freemium model that enables users at a company to start using Yammer without company approval. Yammer used that strategy to grow quickly and gain fans at a company before it tries to sell to a company.
In a related but slightly different area, Salesforce.com recently agreed to acquire Buddy Media for $689 million in cash and stock.
