Vote it up! Mark Zuckerberg, founder and CEO of Facebook. - Photo courtesy Facebook

Microsoft is at it again. The barrel hasn't gone cold and Microsoft has sent out feelers to Facebook for a possible acquisition.

If its last reported 'war chest' of $47.5 billion for the failed takeover of Yahoo is lying unspent, its has lots to spare for Facebook, valued at $15 billion. But that valuation was last reported in October of last year. Microsoft had taken a stake of $240 million in Facebook. That's a 1.6 per cent stake. That time, it was an attempt to solidify an advertising deal between the two companies and block the growing challenge from Google.

Google still remains Microsoft's bête noire but now few months down the line Facebook could be worth a trifle more as its popularity has soared. It is now one of the hottest properties on the Internet with a user base population of 70 million. Mark Zuckerberg has always been disinterested in selling the company instead preferring IPO's.

The talks were first reported by Web site All Things Digital, owned by Wall Street Journal publisher Dow Jones. Facebook and Microsoft have both declined to comment.

It seems that the battle to rival Google is not going to be over till the fat lady sings.