PROVIDENCE, R.I., JAN. 3 -- Gov. Bruce Sundlun, yielding to the anguish of credit union customers whose savings have been put at risk by the state's deposit insurance crisis, promised today that the Rhode Island state government would eventually protect depositors from losses for accounts of up to $100,000.

The governor's commitment brought relief to tens of thousands of Rhode Island depositors, many of whose life savings were invested in credit unions or banks that may never reopen. But the expense will be a heavy new burden on Sundlun's three-day-old Democratic administration, which already is struggling with a $160 million annual deficit in the state budget.

Sundlun made the announcement this afternoon, as the full scope of the emergency became clear with the revelation that the total shortfall to be covered by the state will be between $250 million and $1 billion.

Details of how the state will manage to cover the deposits remained vague and it also was unclear how long it would take depositors to get back their money from 11 credit unions -- including four of the largest in the state -- that the federal government said today it would not insure at present.

The 11 were among 45 financial institutions that Sundlun closed Tuesday after their private insurance fund suffered a financial collapse. Twenty-two credit unions have now been granted federal insurance and are expected to reopen next week, while the future is unclear for 12 banks and other institutions that were closed.

In making what he called a "commitment" to cover depositors' losses up to $100,000, even though the state is not legally obliged to do so, Sundlun responded to heavy political pressure from the state assembly, aides said. The feeling in the legislature was described as unanimous that small depositors should be covered in full.

Tens of thousands of families, including Ann and Raymond Maglio of Johnston, have been cut off from their savings. Their dream of buying a Florida home for their retirement depends now on the governor's pledge to make good their loss, because they have more than $15,000 in two individual retirement accounts at Columbian Credit Union, one of the 11 that today was officially declared unworthy of getting the federal insurance that it needs to reopen.

"That was what we were hoping was our retirement money," Ann Maglio, 50, said today as she made bouquets at the Almacs supermarket where she works. She was worried that her husband, a retired repairman, would be angry with her because she insisted 10 years ago on putting the IRA money in Columbian, rather than a federally insured bank, to get an extra half a percentage point of interest.

"I think it stinks," she said before the governor made his pledge. "It's a little bit scary, to think you've been putting money in an IRA all these years, and it's gone."

For John Evers, a 15-year-old newspaper carrier, the banking crisis may mean that he has to wait for a new car that he was hoping to buy next year. Evers has savings of nearly $3,000 -- or about 15 months' work -- deposited in Greater Providence Deposit and Trust, a bank whose fate is unclear because the federal government has not indicated whether it will step in to insure the deposits. "I'm just worried. I hope I can get my money back," Evers said.

Pat Marandola, owner of a small grocery store in North Kingstown, revealed a different side of the crisis that has struck this small state. All of his business receipts were deposited in the Davisville Credit Union, one of those ordered closed, and now he is struggling to meet his payroll and other expenses. A sign on his cash register said no checks would be accepted from any credit union, the Associated Press reported.

"It stops me from everything," he said. "It's a snowball effect. I'll survive, but it's going to screw me up."

Sundlun said that he hoped to minimize the state's burden in protecting depositors by arranging the purchase of one or more of the uninsured credit unions. The state also might promise to cover any losses suffered by the federal government if it agreed to insure the credit unions, or it might extend a similar pledge to a potential purchaser of them.

If such steps prove inadequate, Sundlun said the state would pay cash or issue scrip to cover depositors' losses. "It will be our policy to see to it that the depositors ... receive payment for their deposits up to a limit of $100,000," he said.

Estimates of the potential cost to the state varied widely. Sundlun said federal regulators told him last month that coverage of depositors' losses would cost the state between $475 million and $1 billion, but he thought those estimates were too high.

A senior state official, who asked to remain anonymous, said that the governor believes that a more realistic estimate is about $250 million. Either way, the expense is devastating for the Rhode Island state budget. With a deficit estimated at 12 percent of its total budget, Rhode Island already has the highest deficit, measured as a percentage of spending, of any state government in the country.

Sundlun, responding to widespread public suspicion that corruption and illegality were at the root of the crisis, also announced that Vartan Gregorian, president of Brown University in Providence, will prepare a report on the problem. The state attorney general will assist in the study. An initial draft is due in 30 days.