Montevideo - Former guerrilla fighter Jose Mujica, the candidate of the leftist ruling-coalition Frente Amplio, won Sunday's election in Uruguay with 47.49 per cent of the votes, preliminary official results confirmed Monday.

Such a percentage, however, was not enough for Mujica to avoid a runoff November 29 against conservative Luis Alberto Lacalle, who had 28.53 per cent of the votes based on the full count.

Pedro Bordaberry - the son of former Uruguayan dictator Juan Maria Bordaberry, currently under house arrest for human rights violations - got 16.66 per cent of the votes.

The top two finishers will clash in a runoff, with the definitive winner succeeding outgoing President Tabare Vazquez on March 1 with a five-year mandate.

"Society demands from us an additional effort, to take part in a second round," Mujica said late Sunday. "We have a very optimistic starting point."

Mujica, 74, is a former member of the leftist guerrilla group Tupamaros and took part in robberies and kidnappings, among other crimes, in the past. He spent 15 years in jail, before holding public positions including agriculture minister.

Voting took place without major incidents, with about 90 per cent of around 2.6 million registered voters casting their ballots.(dpa)