Wal-Mart Stores Inc is launching an online discount sale on Wednesday to counter Amazon.com Inc's highly-publicized "Prime Day", a shopping event for members of its Amazon Prime service on the same day.

The world's largest retailer also cut the size of the minimum order eligible for free shipping to $35 from $50 for at least 30 days.

The discount sale will offer rollback prices, or discounts, on more than 2,000 items including electronics, toys, baby and home products for three months, spokesman Bao Nguyen said.

Amazon on its website touts "Prime Day" as offering "more deals than Black Friday" to members of its $99-a-year Prime shipping and digital content service.

Wal-Mart's Nguyen said the company might explore extending the free shipping offer depending on the response to the sale. It will also offer certain limited-time deals, called "atomic deals," details of which it will provide later.

The sale will only be on Wal-Mart's U.S. website.

"We've heard some retailers are charging $100 to get access to a sale," Walmart.com Chief Executive Fernando Madeira said in a blog post.
"...The idea of asking customers to pay extra in order to save money just doesn't add up for us."

Wal-Mart's shares were up 1 percent at $73.94 on the New York Stock Exchange on Monday.