TORONTO (Reuters) - Some of Wal-Mart Stores Inc's (>> Wal-Mart Stores, Inc.) Canadian locations stopped accepting Visa Inc (>> Visa Inc) credit cards on Monday, the retailer said, after it failed to reach a deal over what it called "unacceptably high" fees.

In a rare example of negotiations between a major retailer and credit card company spilling out in public, Walmart said last month it had been unable to agree with Visa on an "acceptable fee" and would no longer accept the company's credit cards unless it got a better deal.

The decision to stop taking Visa in three stores in Thunder Bay, Ontario, will eventually be mirrored across the more than 370 outlets in the country, Walmart Canada said in a statement on Monday, though it did not give details.

The decision will not affect stores outside Canada, the company said. A spokesman added that Walmart was "optimistic that we will reach an agreement with Visa."

Canadian retailers have long complained about what they call the high interchange fees they pay credit card companies, though representatives of Walmart Canada and Visa have declined to address questions on specifics of payment terms.

Visa has taken up ads in several Canadian newspapers, saying Walmart is using its customers as pawns in its bid to get lower fees.

Visa "remains committed to doing everything reasonable" to ensure its cards can be used at Walmart stores, a spokeswoman said in a statement.

(Reporting by Ethan Lou in Toronto; Editing by Jeffrey Hodgson)

Stocks treated in this article : Wal-Mart Stores, Inc., Visa Inc