Projections: Sanguinetti to Lead Uruguay : South America: The former president wins close vote. Election is first in which third group has seriously challenged two traditional parties.

Former President Julio Maria Sanguinetti won the presidential election in a close, three-way contest Sunday, according to projections based on incomplete official returns.

Sanguinetti, 58, and his traditional Colorado Party defeated the governing National, or Blanco (White), Party and the leftist Broad Front coalition, the polling firm Cifras declared. Its projections gave the Colorados 33.5% of the vote against 31% for the Blancos and 30% for the Broad Front and its allies, who ran as the Progressive Encounter.

In declaring Sanguinetti the winner early today, Cifras said the trend was “irreversible.” Projections by another firm, Equipos Consultores, confirmed Sanguinetti’s victory.

Sanguinetti will take office March 1, five years after ending his first term. The veteran political insider previously served as a congressman, minister of industry and commerce and minister of education and culture. He will succeed President Luis Alberto Lacalle of the Blanco Party.

During the campaign, Sanguinetti portrayed himself as a social democrat. He criticized Lacalle for rushing into the Mercosur free-trade agreement with neighboring South American countries without adequately preparing Uruguay for foreign competition.

“Today we are all workers in the foundry of Uruguayan democracy,” Sanguinetti said in a short victory speech to cheering supporters. “I simply say I assume this responsibility understanding that I must be the first in effort.”

A total of 20 presidential candidates ran. Sanguinetti’s closest rivals were lawyer Alberto Volonte and former Interior Minister Juan Andres Ramirez of the governing National Party, and Socialist Party physician Tabare Vazquez of the Broad Front coalition.

The race marked the first time that a third political force has seriously challenged the Colorado and Blanco parties, which have dominated Uruguayan politics for 158 years. The Broad Front coalition includes Vazquez’s Socialist Party, the Communist Party and former Tupamaro guerrillas.

In 1973, when Tupamaro violence shook Uruguay’s political foundations, the armed forces shut down the Congress and imposed a harshly repressive regime. Sanguinetti, elected in 1984, was the first civilian president after military rule.

Sanguinetti’s Colorado Party lost power in 1989 elections, and Lacalle took office in March, 1990. The constitution bars presidents from running for successive terms.

The Broad Front won 21% of the vote in 1989, nearly 18 percentage points behind the winning Blancos. Analysts attribute the growth of the Broad Front partly to Vazquez’s popularity in Montevideo, where he was mayor until July.

Voters also have grown impatient with Uruguay’s slow economic recovery under Colorado and Blanco administrations after decades of stagnation and decline, the analysts say. Many young Uruguayans, less steeped in the two-party system than their parents, voted for the third force.

Washington Aguirre, 19, said he voted for the Broad Front because he wants to try something different from the Colorado and Blanco administrations he has seen. “I didn’t like them,” Aguirre said. “It’s always the same, always traditional. They don’t change things.”

Sunday’s balloting was also for mayors and members of Congress. The next president will face the challenge of getting legislation through a Congress in which an array of opposition parties will hold an overwhelming majority.

Another challenge for the five-year administration will be adjusting Uruguay’s small economy to Mercosur, which eliminates import tariffs beginning Jan. 1 among Argentina, Brazil, Paraguay and Uruguay.

The market of 200 million people offers new opportunities for Uruguayan industry and agriculture but also opens them up to competition from stronger and more advanced producers.

The Uruguayan constitution allows more than one presidential candidate from each party, and each party’s first-place candidate gets all his party’s votes. The Colorado Party had four presidential candidates; the Blanco Party, three; and the Broad Front, one.