LIMA, Peru - Unofficial results showed leftist military man Ollanta Humala narrowly winning Sunday's bitterly contested presidential runoff against the daughter of disgraced former President Alberto Fujimori after promising the poor a greater share of Peru's mineral wealth.

Results announced by the independent election watchdog group Transparencia gave Humala 51.3 per cent of the vote against 48.7 per cent for Keiko Fujimori with more than 90 per cent of the ballots counted. The error margin was one percentage point.

Official results were not expected until later Sunday night, but Transparencia's track record in previous elections is solid.

Rife with mudslinging and dirty tricks, the election was marred by doubts about both candidates' commitment to democracy. Fujimori's father is serving a 25-year prison term for rights abuses and corruption and she shares the same inner circle of advisers. Humala has been accused of violent excesses as an army counterinsurgency unit commander in the 1990s.

Humala, 48, allied himself closely with socialist Venezuelan President Hugo Chavez in his first run for the office in 2006, which he narrowly lost to Alan Garcia. This time he softened his radical rhetoric and disavowed Chavez, promising instead to follow Brazil's market-friendly model.

He failed to win over the business elite, however, which fears Humala will nationalize industries and expropriate private property. His champions were Peru's neglected -- the one in three people who are poor and have gained little or nothing from a mining bonanza that fueled economic growth average 7 per cent a year since 2001.

Humala finished first in the election's April 10 first round, when three centrist candidates together split 45 per cent of the vote. He got a big boost with the endorsement of fourth-place finisher Alejandro Toledo, Peru's president in 2001-2006.

Earlier, Toledo had warned that a vote for Humala was "a jump into the abyss."

Had Toledo and the other two centrist candidates united behind a single candidate they could have easily kept Keiko Fujimori out of the runoff. But Peru is a country where personality decides elections rather than political party affiliations. Its parties are weak, its political class considered extremely corrupt.

That opens the door for outsiders like Humala and Fujimori's father, Alberto. He vanquished hyperinflation and fanatical Shining Path rebels during his autocratic 1990-2000 presidency.

A fifth of Peruvians revere the man, but his legacy of corruption hurt his daughter, a 36-year-old congresswoman. Humala harped on it. He vowed to throw corrupt politicians in jail and make it easier for citizens to recall their elected leaders.

Both candidates promised a raft of giveaways for the poor, including free school meals and preschool care. Humala promised a government pension for all at age 65.

But, unlike his opponent, Humala also insisted on taxing windfall mining profits and exporting less natural gas so it is cheaper for Peruvians.

That got him the vote of Isabel Apaza, a 56-year-old street vendor.

"Peru has so many riches, so many natural riches from which the people earn a pittance," she said in Villa el Salvador, a poor, sprawling district of Lima.

Humala backed down during the runoff campaign from early calls for renegotiating free trade agreements and rewriting Peru's constitution to "create an economic regime with social justice as its objective."

Two weeks ago, he swore on the Bible to respect democracy and press freedom.

"I will be a president who acts only within the constitution and the rule of law," he said.

Humala insisted he'd steer Peru closer to the United States and Brazil than to Chavez's leftist camp, which includes Venezuela, Bolivia and Ecuador, none of which currently have U.S. ambassadors.

Former New Mexico Gov. Bill Richardson, in Peru as an Organization of American States election observer, met with both candidates and said he didn't consider Humala another Chavez.

"He is a nationalist and an enigma with evolving views and a pragmatic streak," Richardson said. "I think he's educable and the business community should give him a chance."

Humala's spokesman, Daniel Abugattas, stressed Sunday evening that he wanted Peruvians to understand clearly that his boss has no intention of expropriating either land or businesses.

"National and international investment and private property are absolutely guaranteed," Abugattas said in a TV interview. "There will be no taxes on your chickens nor will your house be take away."

Skeptics fear Humala will put Peru on a course similar to the 1968-75 leftist military dictatorship of Gen. Juan Velasco, for whom Humala expressed esteem during the 2006 race.

At stake, for starters, is the potential for losing more than $40 billion in investment pledged over the next decade to develop Peru's mines of gold, silver, copper and other metals.

"He's going to change the constitution and stay in power. And the investors are going to go away, too," said Luis Rodriguez, a Villa El Salvador street vendor who voted for Keiko Fujimori.

But more voters apparently feared a rerun of the autocratic, kleptocratic regime of Alberto Fujimori. Many Peruvians believed he was running the campaign from a Lima police compound where he enjoys spacious quarters and frequent visitors.

Human rights questions also dog Humala, however.

He was accused but never tried for rights abuses as a counterinsurgency commander in the 1990s. And in a radio address from Korea, where he was military attache, he encouraged a 2005 revolt against Toledo by his now-imprisoned brother, Antauro, that claimed the lives of four policemen.

Juan Antonio Herrera, a 64-year-old bookkeeper, called Humala "a simple soldier without schooling. He nearly committed a coup d'etat."