In a move that bank trade groups applauded, the Treasury Department said Sunday that its plan to guarantee money market mutual funds would cover only the amounts held in those funds at the close of business Friday.

The Independent Community Bankers of America and the American Bankers Association welcomed the concession, saying it would eliminate the incentive for people to move money from bank accounts into the higher-yielding funds.

"This certainly helped a great deal," Camden Fine, the ICBA's president and chief executive, said in an interview Monday.

However, Mr. Fine said community bankers have other concerns with the plan. One of his group's goals is to set a ceiling of $100,000 per account for the guarantee, mirroring the limit on deposit insurance.

Bank trade groups immediately objected Friday when the Treasury announced its plan to backstop the funds. The groups argued that the plan would make it harder for banks to attract and retain deposits, since consumers could earn better yields in money market mutual funds and their principal would not be at risk.

In a brief announcement Sunday, the Treasury said the details of its temporary guarantee program were still being finalized. It also said that the coverage would not be extended to any amounts moved into money market mutual funds after Friday, and that both tax-free and taxable funds would be included.

"A big question I have is: Once this guarantee is in place, does anybody seriously believe they'll just withdraw it after a year?" Mr. Fine asked. "I'm hoping what they say is true, and it's only a temporary measure, but once you extend insurance to a class of the general public, it's very hard to take that away."

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