Microsoft is in talks to buy social network company Yammer, reports Bloomberg, citing two undisclosed sources.

According to the report, the software giant is predicted to pay more than $1bn for the San Francisco-based start-up, with the deal expected as soon as tomorrow.

Business Insider also reported the Yammer office has been “abuzz since Monday” with talk of the acquisition.

Yammer recently announced integration with CRM solution Microsoft Dynamics, which Alan Lepofsky of Constellation Research described as a great indicator of the platform's existing success. 

The acquisition would see Microsoft joining the “social arms race” following Oracle’s recent acquisition of Collective Intellect and Vitrue; SAP’s purchase of Cloud-based business commerce network Ariba; and Salesforce.com’s recent acquisition of Buddy Media.