The world's book trade meets in Frankfurt this week on the brink of a long-feared transformation of the industry for which few are well prepared.

Electronic reading devices like Amazon's Kindle are set to enter the mass market, starting with a surge in sales this Christmas holiday season, helped by lower prices, rising consumer confidence and better distribution outside the United States.

Like the music and newspaper industries before it, the book-publishing world now faces vanishing revenues as sales of physical discs, papers and books give way to far cheaper or free digital distribution.

"Meantime, publishers are distracting themselves by fretting over the price of eBooks, withholding eBook releases so as not to cannibalize hardcover book sales, and watching helplessly as their businesses erode in front of them," analyst Sarah Rotman Epps of technology research firm Forrester wrote this week.

Forrester estimates three million e-readers will be sold in the United States this year and double that number next year, taking the total sold to 10 million by the end of 2010 - excluding other digital screens, such as phones and PCs.

There are exceptions in the book industry to the general lack of enthusiasm for all things digital.

Bookseller Barnes & Noble is expected soon to launch its own e-reader, which would provide strong competition to the Kindle and Sony's reader in the market for book-sized screens that grab and display text from the web.

The company has declined to comment on reports it will soon sell its own wireless touchscreen reading device. "We believe readers should have access to books in their digital library from any device, anywhere and anytime," a spokeswoman said.

Most of Barnes & Noble's electronic titles at launch were out-of-copyright books in the public domain supplied by Google, which wants to scan all the world's books and make them available online.

So far, the internet giant has scanned 10 million books through agreements with libraries and publishers, but it has made enemies along the way by scanning library books without always gaining prior permission from the rights holders.

Now Google seems to be on the verge of settling a mammoth lawsuit with US publishers. A final court hearing takes place on November 9 on the settlement, which would entail Google's helping to set up a books registry to track down and pay rights holders.