A federal appeals court says it is too early for authors to be considered as a group in litigation challenging Google Inc.'s plan to create the world's largest digital library.

The 2nd U.S. Circuit Court of Appeals said in a ruling Monday that a judge must consider fair use issues before deciding whether to consider authors as a class. The court says neither side will be harmed by a delay in deciding whether the Authors Guild can represent all writers.

So far, Google has copied more than 20 million books. The three-judge appeals panel that heard arguments earlier this year seemed reluctant to get in the way of the plans. One judge said it would be a "huge advantage" for many authors while another said it would have "enormous societal benefit."