SAO PAULO, Brazil -- Unemployed construction worker Antonio da Silva has not made up his mind how to vote in Sunday's presidential election, but he does know what he expects from Brazil's next leader.

As he scanned help-wanted ads on a wall in Sao Paulo, he talked of the need to create jobs and make fewer promises.

"It's all, 'Blah, blah, blah,' but there's still not enough jobs. I don't know yet who I'll vote for," he said.

The outcome of Sunday's vote could hinge on undecided voters like da Silva, 42, who is not related to Luiz Inacio Lula da Silva, the Workers Party candidate leading opinion surveys.

Polls show Silva, a former union boss who lost his last three bids for the presidency, commanding a runaway lead and falling just short of the 50 percent-plus-one vote tally he needs to avoid an Oct. 27 runoff.

Economy is the issue

At issue is Brazil's ability to revive a sputtering economy -- the largest in Latin America -- and attract the foreign capital needed to finance continued expansion. Failure could lead the government to default on $100 billion it owes to foreign banks.

The government-backed candidate, Jose Serra, lags behind Silva by some 30 percentage points but leads two others: the populist former governor of Rio de Janeiro state, Anthony Garotinho, and former finance minister Ciro Gomes, leader of the center-left Labor Front coalition.

David Fleischer, a political scientist at the University of Brasilia, said Silva, widely known as Lula, has a good chance of winning it all Sunday.

"Lula is very shy of victory," Fleischer said. "He is just a half-point or 1 percentage point away from the simple majority he needs."

Fleischer did not rule out a late surge of votes for the leftist Silva.

"People often jump on the bandwagon of the candidate who appears to be winning," he said.

"Lula's strengths are that he has moderated considerably to the center and is more palatable to the people. Lula is now probably the best brand name in Brazil after Coca-Cola because he's been around a long time."

In 1989, Silva lost to center-right populist Fernando Collor de Mello. He lost again in 1994 and 1998 to current President Fernando Henrique Cardoso.

Now, with Cardoso legally barred from running for a third term and many Brazilians disillusioned with free-market reforms, Silva's chances have never looked better.

Ahead of the ballot, authorities conducted last checks on a computerized voting system introduced in 1996 municipal elections and being used for the first time in a presidential vote.

Sunday's election will use 406,107 electronic voting machines spread among thousands of polling stations across Brazil, whose territory is larger than the continental United States.

The devices consist of a small screen and a telephone-style keypad that authorities say will assure a transparent election. Brazilians previously voted on paper ballots, which were counted by hand, results often took a week or more as those ballots came by canoe and horseback from remote Amazon villages.

In other developments, authorities in Rio de Janeiro asked the federal government for army troops to patrol that state during the nationwide vote for president, state governors, and state and federal lawmakers.

Although the election run-up has been peaceful, Rio's authorities are still jittery after many stores and schools closed Monday amid fears of drug-gang violence that never materialized.