Shares of financial services company Affirm Holdings Inc (AFRM) tumbled over 6% in Monday’s pre-market session after Swedish fintech firm Klarna disclosed it will be partnering with consumer finance app OnePay to exclusively offer installment loans for purchases at Walmart in the United States.

Swedish fintech firm Klarna will be the exclusive provider of buy now, pay later loans for Walmart, taking a coveted partnership away from rival Affirm, CNBC has learned.

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.