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.

Earlier today, it was reported that Affirm (NASDAQ:AFRM) had been pushed out from one of the largest retailers in the world. Klarna, expected to soon become a