Swedish payments firm Klarna said on Monday it is partnering with consumer finance app OnePay to offer installment loans for purchases at retail giant Walmart in the United States.

The move will provide Walmart's customer base with payment options, with direct integration at checkout planned this year.

KEY TAKEAWAYS Affirm shares are tumbling Monday after rival Klarna, which is preparing to go public in the U.S., said it is now the exclusive provider of Buy Now, Pay Later loans for Walmart.Klarna said it would be partnering with OnePay to provide Walmart consumers with installment loans.