Brazil's ruling party has made gains in Sunday's local elections seen as mid-term referendum on the government of left-leaning President Luiz Inacio Lula da Silva.

With 90 percent of the votes counted, reports early Monday indicate Mr. da Silva's Worker's Party will score outright victories in mayoral races in six of 26 state capitals, and will compete in run-offs in at least eight others later this month.

One key run-off will be in Sao Paulo -- the country's financial and industrial capital -- where the ruling party incumbent (Marta Suplicy) is battling to keep her job.

Preliminary results also indicate Rio de Janeiro conservative mayor (Cesar Maia of the Liberal Front Party) has been re-elected. He is considered a possible contender against President da Silva in 2006.

Brazilians voted Sunday for mayors and other local officials in more than 5,000 towns and cities.