Add Washington Mutual to the list of banks cleaning up the mess made by the credit markets during the third quarter.

WaMu, which is one of the country's biggest mortgage originators, said its profit will likely fall 75 percent from the same period last year, as the weak housing market and credit crunch weighed on its business. The bank also said it will set aside $975 million to cover future loan losses, and it will write down $150 million for mortgage loans it plans to sell.

A 75 percent drop in net income would result in the lowest profit the bank has recorded since 1998.

The move follows announcements earlier this week by Citigroup and UBS, which each expect to record billions of dollars in write-downs to cover losses from mortgage-related securities.

In announcing the news, WaMu C.E.O. Kerry Killinger tried to strike an optimistic tone for the future. "While we're disappointed with our anticipated third-quarter results, we look forward to an improved fourth quarter as we continue to see good operating performance in our retail banking, card services, and commercial group businesses," he said in a statement.

WaMu will officially announce its quarterly results on October 17.