One of the country's largest publishers, Penguin Group (USA), is temporarily restoring libraries' ability to loan their e-books for Amazon.com's Kindle - but only through the end of the year.

The publisher backtracked Wednesday after saying it was informed by Amazon.com Inc. that the wasn't aware of Penguin's agreement with Overdrive, a leading supplier of e-books to libraries.

Penguin had suspended making new e-books available to libraries and said it won't allow libraries to loan any e-books for the Kindle due to unspecified .

Amazon allows its Prime express shipping users to read an e-book a month for free from a selection of titles. Though major publishers don't participate, they discovered their books were still being included, a policy denounced as illegal by the .