Google News Archive Search lets users explore existing digitised newspaper and magazine articles and the service will launch today.

Google built the service's index with links already in its general web search index, as well as with links it gained access to through arrangements with publishers and news aggregators, said Jim Gerber, Google's content partnerships director.

The service ranks results based on their level of relevance to the query, and preference isn't given to links from Google partners, which include The New York Times, Factiva, Time Magazine and The Wall Street Journal.

The service covers roughly the history of the past 200 years and results can be grouped in various ways, including by timelines, topics and publishers.

Google News Archive Search doesn't return links to multimedia content, nor does it include links to reference material like books and encyclopedias, said Anurag Acharya, a distinguished engineer at Google. It's not linked with Google's Book Search service.

The links lead both to free and fee-based articles. Google merely provides links and doesn't get involved in monetary transactions between users and publishers for access to the articles. There is no integration with Google's Checkout online payment system, he said.

The new service has no monetisation model, and there is no financial arrangement between Google and the publishers it is partnering with, Acharya said.

Google News Archive Search is launching with a US-English language interface, although it contains content in other languages. The plan is to make it more global through collaboration with international partners, and to launch it for other countries.