Barnes & Noble Inc. is removing from its consumer and college bookstores 100 graphic novels published by Time Warner Inc.’s DC Entertainment unit in a move that underscores the increasing tensions between book publishers and retailers over exclusive content.

Barnes & Noble’s move follows the Sept. 29 disclosure by DC Entertainment that it struck an exclusive agreement with Amazon.com Inc. to make the titles available for Amazon’s upcoming Kindle Fire tablet, expected to ship Nov. 15. The books include “Watchmen,” “Batman: Arkham City” and “Superman: Earth One.”

Barnes & Noble, which is expected to introduce a new Nook tablet series, said it made the decision to remove the titles from its consumer stores on Thursday. Barnes & Noble has previously stated that it expects to be able to sell all formats of all titles that it stocks. The company said it hasn’t take such an action in the past.

“We are disappointed that Barnes & Noble has made the decision to remove these books off their shelves and make them unavailable to their customers,” said DC Entertainment in a statement issued Friday afternoon. “DC Entertainment will continue to make our content available to our fans and new readers through multiple distribution channels including independent bookstores, locally owned comic book retailers and other widespread means such as online through Amazon and through our apps on iOS and select Android-powered devices as well as new and exciting devices going forward.”

But B&N made an odd move backwards by saying they will continue to sell the graphic novels online. The titles will also be available in the stores on a special-order basis only, as long as the books are shipped to a consumer’s home. Barnes & Noble’s decision to exclude the titles from its consumer stores was reported early Friday morning by the Web site bleedingcool.com, which writes about the comic-book industry.

“Our policy is that we won’t stock physical books in our stores unless we’re offered the content in all formats,” said Jaime Carey, the retailer’s chief merchant, in an interview. “We want to maintain a premiere customer experience.”

Barnes & Noble College Booksellers on Friday afternoon began removing the titles as well. Altogether, Barnes & Noble has 705 consumer stores and 636 college bookstores.

The decision comes at a time when Barnes & Noble accounts for as much as 26%-to-27% of the e-book market. At a time when physical book sales are under duress, Barnes & Noble has staked its future on its ability to compete in the digital marketplace via the sale of e-books and its own line-up of Nook e-book readers.