Microsoft is taking on Google, and book publishers worldwide, by introducing its own book search engine. 

Windows Live Book Search is currently available to US surfers and includes collections from the British Library, University of California and University of Toronto.

The service will initially cover non-copyrighted books, but will later be expanded to include protected works with the publishers' agreements.

"We feel very strongly about copyright. We do not do any mass scanning of in-copyright works," Danielle Tiedt, general manager of Live Search Selection at Microsoft, told the BBC. 

"What we are focusing more of our efforts on for live searching is integrating all of those content types to give users the most relevant results.

"If, for example, it's a search on historical content, chances are the most authoritative content may be found in a books search."

Google was sued by the US Authors Guild in September 2005 for its Book Search, which was accused of widespread copyright infringement at the expense of the rights of individual writers. 

In June this year French publisher La Martinière Groupe filed a lawsuit against the search giant, alleging that Google Books amounts to "counterfeiting " and "breach of intellectual property rights".

The publisher demanded damages of €100,000 for each scanned book.