Social networking site Facebook tried to discredit search giant Google by hiring a public relation firm to spread anti-Google stories across media and encouraging outlets to examine allegations of Google’s privacy practices, said a report.

The Facebook's management admitted on Thursday that they were involved in hiring the firm to write negative stories on Google.

There's always been a cold war with skirmishes on varying fronts since Facebook came on the scene so big, said Dan Olds, an analyst with Gabriel Consulting Group. They increasingly see themselves as rivals with Google for advertising dollars. This shouldn't be a surprise to anybody. The competition? It'll probably go even farther. We'll see more hard-nosed competition coming, said a report in Computerworld quoting the analyst.

After Google had its new CEO, the search engine company turned its focus on social networking, sharpening the competition with Facebook, which has more than 500 million users and emerged as the largest social networking site.

This is the biggest threat to Google -- being disrupted by Facebook, said Colin Gillis, a financial analyst. I think Microsoft is attacking the existing business but the real disruption in future business comes from Facebook.

The competition between Google and Facebook increased over the last few months and the two companies are seen battling over acquisition targets as well as over talents and now are seen battling over public perception, sources said.