Amazon, Microsoft, Yahoo unite against Google

They oppose a legal settlement that could make Google the main source for many online works.

"Google is trying to monopolise the library system," the Internet Archive's founder Brewster Kahle told BBC News.

"If this deal goes ahead, they're making a real shot at being 'the' library and the only library."

Back in 2008, the search giant reached an agreement with publishers and authors to settle two lawsuits that charged the company with copyright infringement for the unauthorised scanning of books.

In that settlement, Google agreed to pay $125m (£76m) to create a Book Rights Registry, where authors and publishers could register works and receive compensation. Authors and publishers would get 70% from the sale of these books with Google keeping the remaining 30%.

Google would also be given the right to digitise orphan works. These are works whose rights-holders are unknown, and are believed to make up an estimated 50-70% of books published after 1923.