Google has offered concessions to European publishers who are concerned about the Internet giant's plans to further digitize books by saying that it will not include European books that are still commercially available.

Material which is out of print in the US, but still available for sale elsewhere, will not be added to Google Books, unless consent is granted, the company said on Monday.

Google has already digitized millions of out-of-print titles.

The search giant also said it will let two non-U.S. representatives onto the eight-person board of the Books Rights Registry, which was set up to govern the proposed books settlement reached with U.S. publishers and authors who sued Google in 2005.

Plaintiffs alleged that the company's digitizing initiative amounted to massive copyright infringement.