San Francisco ? Google Inc. will loosen its control over millions of copyright-protected books that will be added to its digital library if a federal judge approves a revised legal settlement addressing the earlier objections of antitrust regulators.

The concessions, filed late Friday in New York federal court, come two months after the U.S. Justice Department balked at Google’s original agreement with authors and publishers, warning the arrangement could do more harm than good in the emerging market for electronic books.

Google, the Internet’s search leader, is hoping to keep the deal alive with a series of new provisions. Among other things, the modified agreement provides more flexibility to offer discounts on electronics books and promises to make it easier for others to resell access to a digital index of books covered in the settlement.

Copyright holders also would have to give more explicit permission to sell digital book copies if another version is being sold anywhere else in the world.

The changes are just the latest twist in a class-action lawsuit filed against Google four years ago by groups representing the interests of U.S. authors and publishers. The suit alleged Google’s ambition to make digital copies of all the books in the world trampled their intellectual rights.

Google negotiated a $125 million truce nearly 13 months ago only to have it fall apart as a chorus of critics protested to U.S. District Judge Denny Chin, who must approve the agreement before it takes effect. The financial terms of the settlement remain intact, including a promise to give 63 percent of all sales proceeds to participating authors and publishers.

Among other complaints, the opposition said the plan would put Google in charge of a literary cartel that could illegally rig the prices of electronic books — a format that is expected to become increasingly popular.

In echoing some of those concerns, the Justice Department advised Chin that the original settlement probably would break laws set up to preserve competition and protect copyright holders, even if they can’t be located.

Under the timeline laid out in the revised settlement, the Justice Department would have until Feb. 4 to file its opinion about the changes. The 30-page brief said the revisions were made after extensive negotiations with Justice Department lawyers.