Amazon limits full-text search's text-search service has been hobbled after an authors' group complained it could slash book sales has disabled the printing feature of its recently introduced "Search inside the book" service after an authors' group voiced concern that it could erode sales of some types of works.

The service lets users type in any keyword and receive results for all the pages and titles of various books that contain that term. Previously, users could search for a book by author, subject or keyword, but could not search the books' contents. The search feature works with around 120,000 titles from 190 publishers, which translates into some 33 million pages of searchable text.

Last week the Authors Guild, a professional organisation representing US writers, recommended that some authors block their works from appearing in the service, arguing the tool could eat into sales of certain types of books, including cookbooks and reference texts. The group says that publishers' contracts don't entitle them to take part in the service without the author's permission, although publishers dispute this claim.

The Guild said that while the tool could benefit older titles and those that don't receive a great deal of attention, the value of reference books and cookbooks would be eroded. This was partly because it was a simple matter to locate and print pages or sections of a book -- something that might particularly appeal to students. Users are only able to view the two pages appearing before and after their search terms, but the Guild said it had been able to print out 108 pages from a book without difficulty.

While it is still possible to print pages by capturing images from the screen, the Author's Guild said on Friday it felt Amazon's changes substantially improved the situation for authors. "Disabling the print function greatly reduces the risk that 'Search inside the book' will erode sales," the Guild said in an email to members. "We believe that most authors should sit tight and see what further technical improvements Amazon makes to the programme before deciding whether to pull their books from the programme."

The group believes the tool could promote sales of many books, but threw cold water on Amazon's claim on Thursday that sales of books included in the programme outpaced sales growth for books outside of the programme by 9 percent.

"We believe that books in the programme are disproportionately more recent titles from larger publishers, which may be growing for reasons quite independent of Amazon's 'Search inside the book' programme," the Guild stated.