Washington Mutual, the sixth largest U.S. bank ($172 billion in deposits), becomes the most high-profile financial institution to officially throw their hat in the direct banking business, looking to stem the tide of high-balance deposits headed to ING Direct, Emigrant Direct, and others.

According to yesterday’s report in American Banker, the bank will begin testing a high-rate deposit product available only from its direct banking unit, WAMU Direct, in four markets: Boston, Philly, Atlanta, and Phoenix.

Apparently the bank will be using the domain name <wamudirect.com> once the transfer of the name is made from the California man who had originally registered it. The bank won rights to the domain name in an arbitration case settled Oct. 14.

—JB