Nicaraguans breathed a sigh of relief tonight as the government junta announced that money they were required to turn in to banks during the weekend will be returned to most of them within days.

The action is likely to diffuse much of a wave of antigovernment criticism and confusion that broke out Friday evening after a surprise decree ordered all large denomination Nicaraguan cordoba notes to be deposited in state-owned banks within 48 hours. The government then planned to have the large notes still in circulation declared worthless.

Popular displeasure was particularly severe about the fact that the original decree ordered that the money be exchanged for six-month time deposit certificates rather than cash. Many in lower economic groups found themselves involuntarily depositing their entire cash savings yesterday and today at a time when both money and employment are in short supply.

According to the junta tonight, however, the entire operation -- including the harsh deposit decree, the public outcry and the surprise announcement that most would get their money back almost immediately -- was an intricately planned scheme to recoup cash from officials of the former government who stole money, while only temporarily inconveniencing the country.

The plan would not have worked, the junta said, if all its details had been revealed from the beginning. Not only was the operation a "stupendous success" in terms of honest cooperation, the government made $18 million on it.

Beginning Tuesday, the announcement tonight said, all of those who deposited less than $300 could take their money out of the bank, in smaller denomination bills. Those with larger deposits will be able to make similar withdrawals in the near future.

This is the way the plan worked:

The initial Friday night decree ordered all 500 and 1,000 cordoba notes, worth $50 and $100 at the current 10 to one exchange rate, to be deposited at banks kept specially open during the weekend. The offer was good for two days only, with the notes declared worthless thereafter.

The junta charged that millions of dollars of the bills, both in the marketplace and lying uncirculated in the government's central bank, had been stolen by officials of the government of former president Anastasio Somoza when they fled the country last month.

To keep the officials or their emissaries from flying back into the country to deposit their money, all commercial flights in and out of Managua were cancelled for the weekend.

Some of the illegally obtained money, the decree said, was believed in the hands of dishonest people still in the country, some of them having taken asylum in foreign embassies here. While junta officials said the idea was that those inside the country would turn in the stolen currency and be caught -- since the central bank had serial numbers of uncirculated bills that disappeared from its vaults -- it seemed unlikely the plan would work since bank tellers reported that none of the deposits were separated by serial numbers. The money turned in during the weekend was simply collected in huge stacks of bills.

What seemed more likely was that those who fled Nicaragua with their pockets full of cordobas -- legal or stolen -- would be out of luck should they try to use them later since the bills are worthless as of Monday. Those inside the country who turned in large amounts of cash would be asked to explain where they got it.

Although the Friday decree was couched in terms of patriotism and the necessity of catching crooks, thousands stood complaining in long bank lines today and yesterday. The Nicaraguan Chamber of Commerce issued a strong statement calling on the junta not to deprive poor people. Businessmen said they would be ruined.

Like Nicaragua's poor, many of them had taken all their money out of savings accounts for safety reasons during the war to oust Somoza. Many individuals whose entire savings consisted of one or two 500 cordoba bills said they did not know how they would feed their families.

Tonight the government announced the return and its explanation.

"When the junta issued its decree," juntia member Sergio Ramirez said on the government radio station, "there were 540 million cordobas circulating in 500 and 1,000 cordoba bills. On Saturday and Sunday, 325 million worth were deposited."

Since the central bank already had approximately 35 million of the bills on deposit in its vaults, he said, that meant a total of 360 million had been accounted for.

Ramirez said that 180 million worth of the large bills in circulation "was not deposited. Most of it is in the hands of Somoza officials inside and outside the country, and in the foreign embassies."

The government eventually will issue new bills in the large denominations for the original 540 million worth not turned in in old bills over the weekend, he said.

"That means we have expropriated the money from the criminals and thieves," he said.

Ramirez announced that more than 60 percent of those who deposited the large denomination bills turned in less than 3,000 cordobas or $300.

All those who deposited up to 1,000 cordobas, Ramirez said "can pick them up [in smaller denomination bills] at the same bank beginning Tuesday. Those who deposited between 1,500 and 3,000 can make their withdrawals beginning Wednesday."

Those who deposited more than 3,000, he said "will have to wait a little longer while we study the situation. When we are sure that the money was honestly come by and has no problems" it will be returned.

"We want to make it clear to the people," Ramirez said, "that this was well-planned for by the junta and the bank." Millions in new 100 cordoba notes were ordered from printers in Britain several weeks ago.

"It wasn't previously announced because we didn't want to allow the thieves to evade it" by dividing up their money "and depositing small sums" that would slip under the limit for redemption.

Ramirez noted that just because the money could be withdrawn, anyone who wanted to leave it in the bank for a while at the service of the government was welcome to. It seemed unlikely the offer would have many takers.