Wal-Mart Stores Inc (WMT) will no longer sell Amazon.com Inc's Kindle products, making the world's largest retailer the second major chain to stop selling Amazon's devices, according to an internal memo and a source familiar with the situation.

"We have recently made the business decision to not carry Amazon (AMZN) tablets and eReaders beyond our existing inventory and purchase commitments," Wal-Mart said in a memo sent to store managers dated September 19. "This includes all Amazon Kindle models current and recently announced."

In the memo, Wal-Mart said the decision was consistent with its overall merchandising strategy. While Wal-Mart dwarfs other retailers in overall sales, it trails Amazon and others online and has been stepping up efforts to increase its presence there. Consumers who buy Kindle tablets such as the new Kindle Fire HD can shop on the devices for more than just digital books, pushing Amazon into further competition with stores.

Searches for "Kindle" on the websites for Walmart and the company's Sam's Club warehouse chain on Thursday brought up items such as cases and screen protectors used with the Kindle, as well as e-readers and tablets from other companies.

Wal-Mart's decision to no longer sell Kindle devices comes months after Target Corp stopped selling the products.

Amazon declined to comment and Wal-Mart could not be immediately reached for comment.