A leftist television journalist made history by bringing a party of former guerrillas to power for the first time since the end of a bloody civil war and promised Monday to unite the country after a bitter presidential campaign.

Mauricio Funes, a moderate plucked from outside the ranks of the rebel-group-turned-political-party Farabundo Marti National Liberation Front, ended two decades of conservative rule in El Salvador in Sunday's election — and became the latest leftist to rise to power in Latin America at a time of uncertainty over how President Barack Obama will approach the region.

"This is not the time for revenge. This is time for political understanding," he told a rally of roaring supporters early Monday. "The time has come for the excluded, the opportunity has arrived for genuine democrats, for men and women who believe in social justice and solidarity."

Funes, 49, rode a wave of discontent with two decades of Arena party rule that have brought economic growth but done little to redress social inequalities. Fuel and food prices have soared, while powerful gangs extort businesses and fight for drug-dealing turf, resulting in one of Latin America's highest homicides rates.

Funes reported for CNN en Espanol on the 12-year war that killed 75,000 people and later hosted a popular interview show.

He has promised to crack down on big businesses that he says exploit government complacency to evade taxes. After winning, he also vowed to promote investor confidence and respect private property.

"There is no time to lose. That's why tomorrow we will start to make decisions necessary for confronting the negative effects of the crisis," he said.

With 90 percent of the vote counted late Sunday, Funes had 51 percent compared to 49 percent for Rodrigo Avila of the ruling conservative Arena party, said Walter Araujo, president of the Supreme Electoral Tribunal.

Avila, accompanied by current President Tony Saca, conceded defeat and wished Funes luck.

Jubilant, red-clad Funes supporters poured into the streets of San Salvador, whooping, clapping, blowing whistles and waving large party flags. Colorful fireworks shot up into the night sky.

Avila, 44, a former police chief, had warned that an FMLN victory would send El Salvador down a communist path and threaten the country's warm relations with the United States. He vowed Sunday to lead "a vigilant opposition that would ensure that the country does not lose its liberties."

Close U.S. ties saw El Salvador keep troops in Iraq longer than any other Latin American country and become a hub of regional cooperation with Washington against drug trafficking. The country's economy depends on billions of dollars sent home by 2.5 million Salvadorans who live in the U.S.

The Obama government has assured Salvadorans it would work with any leader elected — a marked departure from the administration of former President George W. Bush, which in 2004 suggested that an FMLN victory would hurt ties.

But U.S relations with some leftist leaders remain tense, including Venezuela's fiery Hugo Chavez and Nicaraguan President Daniel Ortega, who lashed out last week at the United States for holding back aid over an election dispute.

Funes hopes to start off relations fresh with the Obama administration and promises to respect a free trade agreement with the United States and keep the dollar as El Salvador's currency.

"Integration with Central America and strengthening relations with the United States will be the priority of our foreign policy," Funes said.

During the campaign, television broadcasts were flooded with campaign ads warning that a Funes victory would turn El Salvador into a Venezuelan satellite and emphasizing long-standing ties between the FMLN and Chavez. That stoked fears among many Salvadorans with bitter memories of the 1980-1992 leftist insurgency.

"We don't want communists in this country," said Jose Daniel Avila, a 65-year-old retired pilot of no relation to the candidate. "Look what has happened in Nicaragua and Venezuela. Those are not examples to follow."

Chavez said earlier Sunday that his government was not taking sides in the election, adding that Venezuela wants to broaden its relations with whoever won.