Ken Thompson, a former investment banker, is known as a dealmaker. He created the nation's fourth-largest bank by the 2001 merger of First Union and Wachovia. His last deal, the $24 billion acquisition of Golden West, has proved to be his undoing.

Wachovia has ousted Thompson following an unexpected loss in its first quarter and amid signs that the second quarter is shaping up poorly as well.

The bank's chairman, Lanty Smith, has been appointed interim C.E.O. Thompson was stripped of the chairman's job early in May.

"No single precipitating event caused the board to reach this decision, but a series of previously disclosed disappointments and setbacks cumulatively have negatively impacted the company and its performance," Smith said in a statement. "The board believes new leadership will help to revitalize and reenergize Wachovia and enable it to realize its potential."

But, clearly, most of Wachovia's woes stem from its purchase of Golden West, a California lender that was a pioneer in adjustable-rate mortgages. It was a much-criticized acquisition, one that was made even as the housing boom was fading.

As a result, nearly half of Wachovia's mortgage lending is in California and Florida, two states with some of the highest foreclosure rates in the nation.

Even Thompson acknowledged in February that "With the benefit of hindsight, it is clear that the timing was poor for this expansion in the mortgage business."

In April, the bank said it would cut its dividend by 41 percent and would raise $8 billion from the sale of convertible preferred stock and common shares.

Since then, some Wachovia shareholders have been calling for Thompson's ouster.

Wachovia has also run into some regulatory problems, facing an investigation involving possible money laundering and paying some $144 million to settle accusations that it allowed telemarketers to use its accounts to rip off customers.