Hold on to your smartphone — the holiday price wars between Walmart Inc. and Amazon.com Inc. are heating up.

Walmart, the world's largest retailer, has introduced a program to temporarily lower the price consumers pay for some items on its marketplace site, where third-party vendors pay Walmart a fee to list their goods. The merchants selling on the site, however, will still be paid the same amount that was listed before the cuts, with Walmart subsidizing the difference, according to a description of the plan obtained by Bloomberg that was confirmed by a Walmart spokeswoman. The price reductions won't affect shipping fees.

The move appears to be a response to a program Amazon rolled out over the summer where the e-commerce giant has full control to set prices of third-party products sold on its marketplace — in return for a minimum payout. Amazon has also come under scrutiny for increasingly leaning on vendors to ensure that their products aren't offered for a lower price on Walmart.com or any other rival website.