NEWS ANALYSIS : Brazil Elections Seen as Boost for Collor : Politics: An apparently weakened opposition could aid the president’s free-market policies.

Brazilian congressional and state elections have weakened the leftist opposition to President Fernando Collor de Mello and opened the way for political alliances that could give vital support to his free-market policies.

Centrist and conservative politicians will win a majority of the congressional seats and governorships, according to projections based on exit polls taken during Wednesday’s voting. Conclusive official results are not expected until next week, but as the newspaper Gazeta Mercantil declared Thursday, “It is a clear conservative tendency.”

The big loser in the elections was the socialist Workers’ Party, known by its Portuguese initials, PT. In a December presidential runoff, its leader, Luis Inacio “Lula” da Silva, won 47% of the votes to Collor’s 53%, but the party’s polling strength plummeted Wednesday.

None of its candidates for governor won outright, and only one made it into runoff elections scheduled for Nov. 25. That candidate, Jorge Viana, is running in Acre state, where fellow PT member Francisco “Chico” Mendes, a rubber-tappers union leader and defender of Amazon forest ecology, was assassinated in December, 1988.

The center-left made a strong showing in Rio de Janeiro state, where populist candidate Leonel Brizola beat a PT candidate for the governorship. Brizola, who was the state’s governor in the mid-1980s and an unsuccessful candidate for president last year, now emerges as the country’s leading opposition figure.

He is expected to use the government of Rio de Janeiro, Brazil’s second state in population, and the congressional delegation that he will control as a base for a new presidential bid in 1994. His Democratic Labor Party also has a chance to win governorships in three of Brazil’s other 26 states.

Another early “pre-candidate” for the presidency is Orestes Quercia, the current governor of Sao Paulo state and a leader of the centrist Brazilian Democratic Movement Party, or PMDB. If Luiz Fleury, Quercia’s handpicked candidate, wins the runoff for the Sao Paulo governorship, Quercia will be in a strong position to undermine Collor’s political power.

Collor did not openly campaign for candidates in Wednesday’s voting, but some analysts predict that he will support Fleury’s rival, Paulo Maluf, in the Sao Paulo runoff. Maluf, a conservative, supported the military government that ruled Brazil from 1964 to 1985. He was the losing candidate in a 1984 electoral college vote that returned the country to civilian rule.

Jose Sarney, transitional president from 1985 until last March, received early support from the PMDB, which won 22 of 23 governorships in 1986 elections, and the center-right Liberal Front Party, which won the other governorship then. Both parties, discredited by raging inflation and mismanagement under Sarney, did poorly in last year’s presidential elections.

In Wednesday’s voting, however, the Liberal Front won at least six governorships and the PMDB two, according to polls cited Thursday by the newspaper O Estado de Sao Paulo. In at least 13 states where no runoff is required, the newspaper said, 11 of the winners are regarded as Collor supporters.

A complicated proportional system for electing the 503-seat lower house of Congress has left it unclear how each party did in those races, but analysts agree that the Congress will be dominated by the center-right and inclined to support such Collor projects as balancing the federal budget.

Athough Collor was a fierce critic of Sarney’s administration, most congressional support for the new president’s economic reforms so far has come from the same centrist and conservative parties that supported Sarney. Among conservative legislators not expected to support Collor, however, will be Sarney himself.

Because Collor’s own National Reconstruction Party remains relatively small, the president will have to rely on negotiated alliances to win congressional votes. Control over funds needed by state governments gives a Brazilian president negotiating leverage, but his ability to win congressional support often depends heavily on his ratings in public opinion polls.

Collor has maintained his popularity by lowering inflation from more than 80% when he took office in March to between 10% and 14% in recent months. But if more progress is not made against inflation in the next few months, or if hardship caused by anti-inflation measures deepens, the president’s popularity is likely to wane.

That would open the way for majority alliances against the president, perhaps led by Sao Paulo’s Quercia or Rio’s Brizola.