The Treasury Department is considering a deposit insurance change that could pinch small depositors even though it is aimed mainly at reducing coverage for the rich.

The department asked the Federal Deposit Insurance Corp. for its opinion on whether to restrict each American to three federally insured bank, savings institution or credit union accounts - regardless of how little money is in each, FDIC Chairman L. William Seidman said.The Bush administration, which is expected to offer Congress a comprehensive plan next year to overhaul the banking system, is trying to find a way to thwart wealthy Americans who have developed ways around the $100,000-per-account insurance limit.

Some use brokers to divide their money among a number of institutions. Others use a combination of single, joint and trust accounts to protect more than $100,000. Under existing rules, a couple with one child, for instance, can protect up to $1.2 million at a single bank.

Seidman said Treasury's idea "has some merits and ought to be looked at," but a trade group, the Independent Bankers' Association of America, is vigorously fighting it.

It argues that many Americans of modest means maintain 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 an IRA retirement fund and two $1,000 certificates of deposit - would be allowed to designate only three of them as insured, even though the total - $20,000 - is far below the $100,000 limit.

"I think tens of millions of people would be adversely affected and their financial life rendered more uncertain at just the wrong time," said Kenneth Guenther, executive vice president of the independent bankers' group, which represents smaller, community banks.

"A lot of CDs (certificates of deposit) would wind up not being insured," he said.

However, Seidman said most small depositors likely would consolidate their accounts so that all of their money was guaranteed.

"This is much more likely to cut back on the guy who has quite a bit more money," he said.

A senior Treasury official, speaking on the condition of anonymity, said the definition of an account, for insurance purposes, could be changed so that savers could combine all of their certificates of deposit into one savings account with varying maturities.

The official 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."

However, Guenther's group, citing unidentified "top policy officials," said a limit on multiple accounts is "the reform concept most alive and well in Treasury circles."

The independent bankers have been lobbying against any cutback in deposit insurance. They argue that large banks, which regulators believe must be kept from failing to protect the financial system, would have an advantage in attracting deposits over smaller institutions whose failure would not threaten the system.

But many 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 say.

Treasury Secretary Nicholas Brady said in July that the administration was considering ways to limit depositors to $100,000 coverage, but a letter from Guenther to members of his group was the first indication the administration is considering restrictions that could affect depositors with much less than $100,000.

In an effort to kill the proposal, the trade group on Wednesday sent member banks 250,000 protest postcards, to be filled out by customers and mailed to President Bush.

"We hope by Monday there will be 100,000 postcards at the White House," Guenther said.