EU regulators should look into the book settlement that Google reached with a group of U.S. writers and publishers last October because the deal will create a de facto monopoly, lobby group ICOMP said on Friday.

Google's plan to digitize millions of books is aimed at resolving a lawsuit filed in 2005 by the Authors Guild. Critics say it will allow the U.S. Internet search-engine giant to dominate the digital book market in its infancy.

Earlier this month, Germany and France took their case against the settlement to the Manhattan federal court, which will hold a fairness hearing on October 7. Amazon.com Inc has also argued against the plan. A hearing held by the European Commission on the matter on September 7 and attended by interested parties and Google officials failed to answer critics' questions, ICOMP said in a letter to EU Internal Market Commissioner Charlie McCreevy, Competition Commissioner Neelie Kroes and six other commissioners.

We believe (the settlement) is unacceptable in its present form as it violates the rights of copyright holders and authors and would lead to a de facto monopoly, the Microsoft-sponsored group said.

It queried whether the proposed book database could be accessed only by Google's search engine and if this was the case, whether it would reinforce the company's market share in search advertising. This should be a concern for European antitrust regulators, ICOMP said.

(Reporting by Foo Yun Chee; Editing by Dale Hudson)