By Jessica Wohl

(Reuters) - Walmart is bringing back layaway a month early, giving U.S. shoppers under economic pressure more time to pay for holiday gifts, and will refund related fees with gift cards once payments are completed.

Layaway, which allows customers to keep a product on hold at the store and pay for it over time, helped boost holiday sales for Walmart when it brought the service back in 2011 after a five-year hiatus.

Offering layaway helps retailers such as Wal-Mart Stores Inc win over shoppers without access to credit. Walmart U.S., Wal-Mart's largest unit, also offers check cashing and other services as it tries to appeal to shoppers without bank accounts.

In the past, Walmart has said about 85 percent of transactions in its stores are paid for with cash. Earlier this year it began allowing shoppers to place orders online and pay for them in a store with cash.

Walmart's holiday layaway service will begin on September 16, according to details on the store's website. Last year it began on October 17.

Under this year's plan, customers must pay a $15 fee to open a layaway account, and will receive a $15 Walmart gift card if they complete their payments by December 14.

Last year, customers had to pay a $5 fee, there was a $10 cancellation fee, and customers who paid in full did not get any gift card refund. This year's plan has no cancellation fee.

The down payment of 10 percent or $10, whichever is greater, stays the same. Customers must still spend at least $50 to sign up for layaway, and each item has to be priced at $15 or more.

Walmart also expanded the variety of products available for layaway, adding small appliances and certain sporting goods to the lineup of toys, electronics and jewelry.

Other chains that offer layaway include Sears Holding Corp's Kmart and Toys R Us.

(Reporting by Jessica Wohl in Chicago; editing by John Wallace)