Federal Deposit Insurance Corp. Chairman William Seidman says the savings and loan rescue package pending in Congress would create a giant corporation with as much as $500 billion in assets.

"That institution will be the largest depository institution in the country," Seidman said.The Resolution Trust Corp. that would be created by the legislation could take control of as many as 363 failed savings and loan institutions over the next three years, Seidman said. That includes an estimated 220-225 institutions the FDIC is expected to take immediate control of under President Bush's $157 billion rescue plan.

So far the FDIC has taken control of 215 failed institutions with assets totaling about $88 billion, Seidman said.

Those institutions would be turned over to the RTC once the bill to rescue the savings and loan industry and its insurance arm, the Federal Savings and Loan Insurance Corp., is enacted into law.

But depending on the direction of interest rates and economic conditions, as many as 363 savings and loans with assets totaling between $300 billion and $500 billion could come under control of the RTC, Seid-man said.

He said government control of those assets would be temporary.

"It's not going to stay that way . . . obviously the objective is to move all of that to the private sector," he said.

The government corporation also could end up with about $60 billion in bad assets that were acquired by institutions in deals made last year by the Federal Home Loan Bank Board under the so-called Southwest plan.

Seidman said he saw that much in assets covered by income maintenance agreements, which guaranteed minimum profits to purchasers of failed thrifts, being returned to government control unless economic conditions improve enough to increase their value.

The Bush plan calls for the RTC to review the deals made by the bank board last year. The agency had no money to pay off the depositors of failed thrifts and sought to resolve much of its case load through the sale of failed institutions. But many of those deals have been criticized as giving away too much.

However, a House panel last week rejected measures that would have voided some parts of those deals.