Facebook has been caught hiring a well known PR firm to plant anti-Google stories in the media.

Both Facebook and the PR firm, Burson-Marsteller, admitted Thursday to trying to get journalists and bloggers to write negative articles about Google's privacy practices. The move comes as competition between Facebook and Google has accelerated over the past several months.

The Internet was abuzz with the news that Facebook undertook what many industry analysts and commentators are calling a surreptitious smear campaign against one of its competitors.

"When companies get big enough and grow really quickly... you start to get these rather bizarre political marketing ploys," said Hadley Reynolds, an analyst with IDC. "It certainly isn't serving Facebook or the industry, or Burson-Marsteller, well in this case. The power of social media exposes these shenanigans."

Facebook has denied running a smear campaign.

"No 'smear' campaign was authorised or intended," a Facebook spokesman wrote. "Instead, we wanted third parties to verify that people did not approve of the collection and use of information from their accounts on Facebook and other services for inclusion in Google Social Circles, just as Facebook did not approve of use or collection for this purpose. We engaged Burson-Marsteller to focus attention on this issue, using publicly available information that could be independently verified by any media organisation or analyst."

The spokesman added that the issues are serious ones that should have been presented in "a serious and transparent way."

However, questions arise about a smear campaign because Facebook had allegedly told Burston-Marsteller to keep the company's name out of it. When asked about that, Facebook did not respond.

The entire issue came to light when PR people from Burston-Marsteller contacted blogger Christopher Soghoian, proposing that he write a piece on Google's privacy practices and Google Social Circles in particular. Soghoian, in response, published the string of emails with Burston-Marsteller about the matter.

Social Circles is a feature in Google Dashboard that pulls together a user's publicly available content from social networking sites, such as Facebook and Twitter, and adds it into the user's search results.

Adding fuel to the fire, Burston-Marsteller pitched the same story to USA Today, which ran its own story about the "whisper campaign" to get news media outlets to publish anti-Google pieces.

After the emails and the USA Today story came to light, there was a quick rush of online rumours, with many pointing the finger at Microsoft or Apple as the secretive culprit. However, The Daily Beast followed the trail back to Facebook, where executives at the social network admitted to hiring the PR firm to put out the information on Google.

Google has not commented on the situation. For its part, Burston-Marsteller took some blame for the situation.

"The client requested that its name be withheld, on the grounds that it was merely asking to bring publicly available information to light...," a spokesman for Burston-Marsteller said. "Whatever the rationale, this was not at all standard operating procedure and is against our policies, and the assignment on those terms should have been declined. When talking to the media, we need to adhere to strict standards of transparency about clients, and this incident underscores the absolute importance of that principle."