The Treasury Department is considering restricting each American to three federally insured bank, savings institution or credit union accounts -- no matter how little money is in each.

The department asked the Federal Deposit Insurance Corp. to estimate how much the proposal would save and to describe potential problems in administering it, FDIC Chairman L. William Seidman said yesterday.

Seidman said the idea "has some merits and ought to be looked at."

Treasury Secretary Nicholas F. Brady reportedly has not decided on the idea yet, but it is being advanced by Undersecretary Robert Glauber, the official in charge of the Bush administration's effort to overhaul the financial system.

A senior Treasury official, speaking on the condition of anonymity, stressed that limiting the number of accounts was "one of a number of proposals floating around" and "we are not in any sense embracing it."

A banking trade group, the Independent Bankers Association of America, is vigorously fighting it. "This is not three accounts within an institution -- it is three accounts per individual, period," it said.

Glauber is directing the preparation of a department study, due next month, that is expected to be the basis of an administration proposal to Congress next year calling for the most sweeping overhaul of the financial system since the Depression.

Economists have cited the broad coverage of deposit insurance as one of the causes of the savings and loan debacle. Shaky institutions have no trouble attracting deposits because the accounts are federally guaranteed, they argue.

Brady in July said the administration was disturbed by rules that permit depositors to protect far more than the $100,000 insurance limit, either by spreading their money among institutions or by dividing their money among individual, joint and trust accounts at a single institution.

The independent bankers group sent an "alert" to its members quoting unidentified "top policy officials" as saying a limit on multiple accounts is "the reform concept most alive and well in Treasury circles." The trade group's letter was the first indication that the administration is considering imposing restrictions that would affect millions of Americans with much less than $100,000.

Many Americans maintain far more than three accounts. For instance, a depositor with six accounts -- $1,000 in checking, $5,000 in savings, $2,000 in a credit union, $10,000 in a retirement fund and two $1,000 certificates of deposit -- would be allowed to designate only three of them as insured, even though the $20,000 total -- is well below the $100,000 limit.

Bert Ely, an Alexandria savings and loan analyst who favors privatizing deposit insurance, said limiting the number of accounts would accomplish little unless the government also finds a way to allow large banks to fail without endangering the financial system.