Google’s settlement with authors and publishers over its scanning of millions of books contained in several university libraries has come under fire recently from critics who argue that Google is effectively creating a monopoly of digital versions of books.

The criticism has centered on so-called orphan books, out-of-print books that are still in copyright but for which rights holders cannot be found.

On Wednesday, in an open letter to members, Roy Blount, the president of the Authors Guild, argued that such criticism was unwarranted.

“I would generally rather be a dissenter, myself, than not,” he wrote. But, he added: “I can’t see any reason to dissent from the settlement over the matter of orphan books.”

These books, he said, are being given an opportunity with the Google settlement — the chance to see the light of day and find readers again. “Google is essentially being accused of cornering the market on the unmarketable,” Mr. Blount, the author of “Longtime Leaving” and “Alphabet Juice.”

“To prevent a monopoly of the orphans, the dissenters would undo a wide range of benefits to authors, publishers and readers,” he concluded, appending a list of benefits of the settlement.

The Google settlement is currently the subject of a Justice Department inquiry and is also subject to court review.