BRAZILIAN PRESIDENT JOSE SARNEY'S visit to the United States last week demonstrated there is, in Mr. Sarney's words, a third path for heavily indebted countries that seek a return to economic sanity.

Brazil's decision to take this third path, through the so-called Cruzado Plan that is designed to be anti-inflationary, seems to bother U.S. authorities in Washington, who apparently would prefer that Brazil adopt the economic prescriptions of the International Monetary Fund.Brazil has rejected that option, which it believes would brake economic growth and aggravate its unemployment problem. Instead, it has implemented a daring program of freezing prices, stopping automatic adjustments for inflation and boosting real wages.

After more than six months, the program, with some fine-tuning, is still working. The economy is growing at a 5 percent to 6 percent rate and inflation is down sharply to about 1 percent a month, although consumer prices rose 1.7 percent in August from July. Employment has risen. Economists seem divided on whether the program will keep working. Sooner or later, some say, serious inflationary pressures will re-erupt.

The Reagan administration's lack of enthusiasm for the Brazilian experiment may include such doubts. U.S. officials also may worry that Brazil's program could lead to more nations flouting the IMF and economic orthodoxy. With that, the already uncertain international economy could become more vexatious.

The Reagan administration also is annoyed by Brazil's restrictive trade practices, export subsidies, its challenge to U.S. proposals for a new international trade round and its slowness in repaying $300 million to the Export-Import Bank.

President Reagan, when welcoming Mr. Sarney last week, delivered a not-so- veiled little lecture on beggar-thy-neighbor policies.

Brazil, with the world's eighth largest national economy, is doing well enough now to start acting more like a mature industrial nation, U.S. officials believe. Brazil obviously has ambitions to become something of a global power.

The country, however, is beset with enormous socio-economic problems. Its per capita gross national product is below $2,000 a year and over a fourth of its population is in the impoverished Northeast. Politically, the nation is making a delicate transition to full democracy, which should be of major interest to the United States.

After all, Brazil occupies about half the expanse of South America and about one of every two South Americans is a Brazilian.

More flexibility on both sides would help. For starters, the Reagan administration could be more accommodating to Brazil's desire to reschedule its roughly $7 billion in debt to industrial nations. Instead, the administration seems to insist that Brazil first get a seal of approval from the IMF.

Brazil also hopes to win a multi-year rescheduling of its much bigger commercial bank debt,to include a further reduction in interest spreads.

Brazil's goal, President Sarney says, is to halve its debt payments from 5 percent to 2.5 percent of the country's GNP. Doing so, he argues, would allow Brazil to grow faster and import more, which should be an encouraging prospect to the United States in particular.

There is some logic for the banks to cooperate. Under the U.S.-sponsored debt rescue plan for Mexico, Mexico's debt service would be pared by roughly that percentage. But Brazil seems to be the better credit risk.

Brazil, for its part, might show more alacrity in paying off the U.S. Export-Import Bank and other official export agencies.

It also should do more, despite intense nationalist pressures, to open its computer and other markets to foreigners - a step that in the long term will clearly be to its advantage. Brazil, Mr. Sarney said, is counting on more foreign investment. Opening markets is one way to get it.

For the full story: Log In, Register for Free or Subscribe