The World Bank warned yesterday that if the Bush administration's program to reduce Third World debt is extended to Brazil and Argentina, governments of major industrial nations could be forced to accept much of the financial risk now borne by the world's biggest banks.

The two countries together owe $80 billion to commercial banks.

In a separate development yesterday, Brazil announced it would resume payments on its debt next year after a moratorium of 18 months. The Brazilian government said it would pay its foreign bankers $490 million early next year, roughly 30 percent of the $1.6 billion it should be paying by that time. A delegation of Brazilian experts, headed by chief debt negotiator Jorio Dauster, has been in New York since Sunday discussing ways to refinance the debt with creditors.

Another Latin American debtor, Uruguay, announced yesterday it had reached full agreement on restructuring its debt.

The World Bank's analysis accompanied the release of its annual world-debt tables, showing that the debt of the world's poorer countries resumed its rise this year after staying virtually unchanged from 1987 through 1989.

The World Bank's analysis reiterated the need for more private bank lending to companies and countries in the Third World, which it said "remains minimal."

The report in general gave a vote of confidence to the "good start" made by the the Bush administration in its Third World debt initiative, known as the Brady Plan, after Treasury Secretary Nicholas F. Brady. Still, the bank's report, in diplomatic language, cited some of the Brady Plan's shortcomings, among them that it does not address the debt problem of some low-income countries that borrowed heavily from quasi-government agencies rather than commercial banks.

Efforts are being made to address this through President Bush's new Enterprise for the Americas Initiative and other proposals.

The bank report calculated that in 1990, Brady Plan packages for the Philippines, Mexico and Costa Rica and a scheduled deal with Venezuela will reduce commercial bank debt by about $11.5 billion.

Resources accumulated for Brady Plan operations for the three-year period starting in 1989 appear adequate, but the report suggested that "continuation of official support and additional resources may be needed."

The bank said that "overall, the debt crisis is somewhat less severe than {it was} two years ago," crediting the Brady Plan and various other debt relief programs.

The total was up more than 6 percent to $1.341 trillion dollars, reflecting both additional loans and a "substantial appreciation in the dollar value" of loans denominated in other currencies, the report said.

But the bank report emphasized the danger of increased exposure for itself and other official lenders. Two-thirds of the funds for Brady Plan debt relief operations are provided by the World Bank and the International Monetary Fund, whose capital is provided by the taxpayers of their member nations. Separately, Japan provides the remaining one-third.

If Brady Plan deals are struck with Brazil and Argentina, the bank report said it "would increase official exposure to those countries significantly, if carried out under the terms and mechanisms used so far. ... The Brady initiative will increase the official sector's exposure further, and correspondingly, increase its risk."

World Bank officials said, "We have to be careful how these deals are done" because the amount of the debt involved is so large.