Deposed Philippine president Ferdinand Marcos illegally diverted interest from U.S. economic assistance funds early this year, a Philippine government investigator said today.

In what appeared to be the first documentation of allegations that Marcos misused bilateral aid money, Teofisto Guingona, chairman of the government's official audit commission, said in an interview that Marcos ordered the withdrawal of $1.75 million in interest from U.S. Agency for International Development funds in January.

Guingona said records showed that the money was withdrawn for payment of Marcos' "miscellaneous expenses" in violation of AID regulations.

A former Marcos official who managed the funds confirmed the withdrawals and said that the diverted interest might have been used in Marcos' campaign for the Feb. 7 presidential election.

In a statement in Washington, the U.S. agency said it had no knowledge of any unauthorized withdrawals of interest from U.S. economic support funds. The funds are held in a special account at the Philippine National Bank, administration officials said. Any withdrawals of interest or principal must be approved by U.S. officials.

Guingona said the money came originally from U.S. economic support funds. He said the Marcos government had periodically transferred interest out of the special account at the Philippine National Bank to a government-owned bank.

In a press release, the former manager of AID's economic support fund account, J. Roberto Abling, acknowledged the withdrawals but said the Marcos government had regarded interest on AID funds as its own.

With the interest, Guingona said, Marcos collected a pool of about $6.5 million in an account at the Land Bank of the Philippines. "The Americans sensed something was going on, but I don't know whether they figured it out before today or not," Guingona said.

Guingona said records he had seen on the AID money showed that, on several dates in January, Abling, who was the executive director of an office that handled the U.S. special account and other Philippine government monies, withdrew a total of $1.75 million from the Land Bank of the Philippines for "payment of miscellaneous expenses as per instruction of the president Marcos ."

Administration officials in Washington said they had no immediate explanation for the discrepancy between Guingona's statements and what they said their records showed. They said they have no confirmation of the Land Bank account or knowledge of a separate bank account for the interest accrued on the U.S. special reserve account.

In January, however, "AID was made aware of the desire by Marcos government officials to make withdrawals of interest from the special account and objected because AID believed the withdrawals would be used for programs not approved by AID," an agency statement said today.

One AID official said the latest bank statement, dated Feb. 28, "suggests no unauthorized withdrawals" from the special account at the Philippine National Bank. The officials said they spoke to auditors of the Philippine commission in Manila, who told them that they have not yet seen the records of the U.S. AID mission in Manila on the special account. The Philippine commission is expected to begin a formal audit Thursday, and the U.S. government has offered its assistance, the officials said.

One AID official said one possible explanation for the discrepancy may lie in the way the Philippine office in charge of the U.S. economic account, known as the ESF Secretariat, operated. Because it also handled other Philippine government money, it is possible that monies from those Philippine accounts were diverted, that other bank accounts were opened, and because they were handled by one office, give the impression that the diversions came from the U.S. account.

Another explanation, U.S. officials said, could be in the way U.S. AID money is disbursed in the Philippines. The Philippine government undertakes construction of approved projects, such as schools, drawing money from the Philippine treasury. After the project is completed, AID officials review the invoices of the project activities and after they are satisfied, U.S. officials authorize the release of money from the special account at the Philippine National Bank to reimburse the Philippine treasury.

In such a process, "the Philippine government might well have gone out and built a school, come back and presented the invoices and got approval to withdraw the money," the official said. "But what happened to the money after that was beyond our control and always has been."

The reported withdrawals came at a time when Marcos was spending heavily in an effort to ensure an electoral victory over Corazon Aquino, the new Philippine president, U.S. and Philippine officials have said.

Investigators probing Marcos' largely hidden financial empire have been trying to discover whether he enriched himself with U.S. military or economic assistance to his impoverished nation, but had not previously documented any diversion of aid funds. Guingona said American officials had seemed unaware of the diversions at the time, and a U.S. Embassy spokesman here said the matter was being investigated.

Embassy spokesman Al Croghan said that, while the interest on the AID money may have been misused, its principal had not been involved.

During the election campaign, Marcos' ruling political party spent huge sums to fund "pork barrel" projects, pay for campaign expenses and buy votes, according to Philippine economists and businessmen. Economists such as Omar Cruz of the independent Center for Research and Communication here estimated that the party's campaign-related spending exceeded $500 million.

In a Cabinet meeting today, Budget Minister Albert Romulo said the heavy campaign spending had been a main factor in leading him to nearly double the government's estimate of its budget deficit. Romulo said Marcos' overspending and the failure to collect many tax revenues had swelled the deficit to about $468 million.

Press reports and government investigators have suggested that during the campaign Marcos used his virtually unchallenged powers as president to draw money from a wide range of government accounts, normally used for anything from buying farm produce to operating Manila's international airport.

"It's easy to speculate on what the money might have been used for, but I can speak only according to the records we've seen," Guingona said. He and Abling agreed that after the election $650,000 had been returned to the pool of interest from the aid money.

Guingona said that his committee was searching for the remaining $1.1 million. "We will seek restitution of the money and file appropriate legal action," he said.

Abling said that he had received orders from Marcos, transmitted through two aides, that he make the withdrawals.

Normally, Guingona said, any withdrawal from the account holding the AID money had to be authorized in agreement with AID officials and only in accordance with vouchers showing that the money was being used for specifically earmarked projects, such as the construction of roads and schools.

Despite the ballooning of the government deficit, President Aquino ordered modest cuts in fuel prices today, and appealed to businesses to pass on all the savings to consumers. Observers said that, although the move will cost the government additional tax revenue, Aquino felt it important to make a visible gesture toward the country's poor.

At the Cabinet meeting, Aquino postponed any decision on whether to dissolve the National Assembly and assume extraconstitutional powers, as advocated by some of her supporters. Her spokesman said she was considering a Cabinet committee plan to hold general elections in November and draft a new constitution.