Washington Mutual [WM], the US' third-largest issuer of debit cards, has revealed that it will move its $20 billion principal payment card programs to MasterCard, bringing to an end a ten year relationship with Visa. The terms of the agreement were not disclosed.

After the conversion to MasterCard, which is expected to begin near the end of 2005, Washington Mutual will issue MasterCard debit cards that can be used at signature and PIN point-of-sale locations, and at all MasterCard ATMs

Washington Mutual currently operates nearly 1,900 retail banking offices and more than 3,200 ATMs in 14 states across the US. The company serves 7.9 million retail banking households, which includes approximately nine million signature debit cardholders and 1.5 million PIN-only cardholders.

Washington Mutual transformed the consumer banking experience by energizing bank branches as never before. Together, we will transform the way consumers pay for everything that matters, said Ruth Ann Marshall, president of the Americas, MasterCard International. We are excited to be the debit card of choice for a financial services pioneer.

MasterCard debit cards are accepted at an estimated 5.6 million merchants in the US, at nearly 1.5 million PIN terminals, and at approximately 383,000 A locations. Collectively, the family of MasterCard brands is a worldwide leader with 24 million locations and growing.

Despite MasterCard’s success in winning the Washington Mutual business Visa still holds a 75% share of US debit card market.