A year after initiating a service which enables internet users to search for blog sites, Google has added the function to Google News.

The overall market size of the so-called "blogosphere" is expected to increase as a result of the decision and some observers are questioning how news and blog content will be distinguished as search engines continue to develop.

Blog searching has been possible on a beta test site set up by Google and only over the weekend of October 21st and 22nd became available on the Google News site, reports e-consultancy.

In recent days, Google acquiesced to a request from one particularly popular political blog site to be removed from the search engine's automated news index, claiming it wanted to maintain its credibility.

Marshall Kirkpatrick of TechCrunch, said of the new service: "It is liable to increase the market size for the whole blogosphere, though not as much as it could have if the link had been added to even the second tier list of services on the front page of Google."

TechCrunch is a weblog dedicated to reporting on and profiling innovative internet products and companies.