In his first full day on the job, Washington Mutual Chief Executive Officer Alan Fishman pledged to return the Seattle savings-and-loan to profitability even as investors grew more doubtful about its prospects.

"I need to sit down and do a real dive into this thing," said Fishman, who was hired to succeed Kerry Killinger after WaMu's board concluded that an outsider was needed to help restore confidence.

Underscoring the magnitude of problems facing Brooklyn-born Fishman is a memorandum of understanding with the Office of Thrift Supervision that was approved by WaMu's board in Sunday's board meeting.

The confidential document forces WaMu to provide the federal agency with what the company called "an updated, multiyear business plan and forecast for its earnings, asset quality, capital and business segment performance." WaMu said it isn't being required to raise additional capital or change any products or services.

Fishman promised to build "a winning model for the future" based on WaMu's 2,300-branch franchise, but he offered few details on how he would limit the company's credit exposure. He played down the need for additional capital and told analysts that it was too early to comment about possible asset sales. If the United States returns to a "more normalized credit environment," he said, the bank could free up $4 billion to $6 billion a year.

Analysts are skeptical that Fishman can come up with quick fixes for WaMu's core problems.

On the New York Stock Exchange composite trading, WaMu shares dropped 82 cents, or 19.90 percent, to $3.30. The shares are down 70 percent this year.

"The problem is very simple: They made a lot of bad loans," said Richard Bove, banking analyst at Miami-based Ladenburg Thalmann & Co. "The solution for their problem is to find some mechanism for reducing the bad loans. That can't be done by a new CEO."