By Kathy Finn

NEW ORLEANS, Oct 14 (Reuters) - Wal-Mart Stores Inc and Xerox Corp blamed each other on Monday after Louisiana food stamp recipients stripped bare the shelves of some Walmart stores when a computer glitch left their debit cards with no limits.

Managers of Walmart stores in the small, north Louisiana towns of Springhill and Mansfield alerted police on Saturday night that throngs of shoppers had flooded into the stores and were buying groceries using electronic benefit cards that contained no credit limits.

EBT cards are debit-type cards issued under the state's food stamp program and coded to show the amount of money available for individuals to spend. Food stamps are a federal government subsidy program for low-income people that is administered by the states.

When word got out Saturday that the EBT cards were showing no limits, card holders rushed to area Walmarts to take advantage.

"Some people had eight or 10 shopping carts full of groceries," Springhill Police Chief Will Lynd said on Monday.

Xerox said on Saturday that its systems that process EBT transactions suffered an outage stemming from routine testing of backup generators that malfunctioned. Louisiana was one of 17 states affected by the outage.

Kayla Whiting, a spokeswoman at Wal-Mart's Bentonville, Arkansas, headquarters, pointed to Xerox as the source of the problem and referred further questions to Xerox.

Xerox corporate spokesman Bill McKee provided a written company statement saying that Xerox has a "documented process for retailers like Wal-Mart to follow in response to EBT outages."

But the statement left unclear who would cover the unauthorized spending, and it referred further questions to Walmart.

Louisiana officials said they had no intention of being left holding the bag. "The outage was the result of failures by our contractor, Xerox," said Trey Williams, a spokesman for the Louisiana Department of Children and Family Services.

He said emergency procedures in place with Xerox allow retailers to call a phone number and receive authorization for purchases any time the EBT system is down. "Some retailers chose not to follow the process," he said. "Those businesses are only being reimbursed for the (maximum) amounts on individual cards," he said.

Williams said that amounts transacted above the cards' available balances were returned to Wal-Mart marked "as insufficient funds."

He could not provide an estimate of the total amount of overspending or say who will cover it in the end. "That's a conversation between Xerox and the retailer," he said.