Ortega declared winner
With more than 90 percent of voting precincts counted, the electoral council said Mr Ortega had won 38 percent of the vote.
Conservative candidate Eduardo Montealegre came in second with 29 percent of the vote, followed by also conservative Jose Rizo with 26.2 percent.
Mr Ortega has won the Nicaraguan vote outright, since by law he had to secure at least 35 percent of the vote and a five-point lead on his closest rival.
“The results favour Daniel Ortega, whom I’ve called to congratulate,” Mr Montealegre, of the National Liberal Alliance, said in a speech conceding defeat.
“He has been elected democratically and will have to govern so,” Mr Montealegre added, hinting at Mr Ortega’s murky past as President of Nicaragua’s leftist Sandinista government from 1979 to 1990.
Guatemalan President Oscar Berger was the first international leader to applaud Mr Ortega’s victory.
“We respect the will of the Nicaraguan people and congratulate Daniel Ortega,” he said told reporters in Guatemala City.
US ‘will work with Ortega’
Earlier former US president Jimmy Carter, who was in Nicaragua to monitor Sunday’s election, said US officials were willing to work with Daniel Ortega if the former Marxist rebel leader “reaches out” first to his one-time enemy.
Mr Carter said on CNN television that he discussed Mr Ortega’s apparent victory with US Secretary of State Condoleezza Rice.
Mr Carter quoted Ms Rice as saying that if the election is certified by international monitors as “honest and fair, and if the Ortega government reaches out in a respectful and supportive way to the United States, then the United States will reciprocate”.
“I think there is no doubt that the future relations between the US and Nicaragua will be improved,” Mr Carter said.
The State Department confirmed Ms Rice’s conversation with Mr Carter Tuesday.
State Department spokesman Sean McCormack noted that Washington had negotiated aid and trade deals with the Nicaraguans, including Sandinistas.
And he left the door open to improved relations.
“We’ll see what government this election produces. We’ll see what the platform of that government is,” he said.
Cold War foe
Earlier, the iconic Sandinista leader and Cold War foe of Washington ran into fierce opposition from US officials during campaigning while enjoying an endorsement from the virulently anti-US Venezuelan President Hugo Chavez.
In Caracas, Mr Chavez said Mr Ortega’s victory was practically assured. “Yankee go home! This land is ours!” he shouted to a group of followers, seeing Mr Ortega’s victory as a step toward his goal to rid Latin America of US influence.
During the campaign, Washington urged Nicaraguans to defeat Mr Ortega, whose Soviet-backed Sandinista government seized private assets, distributed land to poor farmers and battled US-financed Contra rebels throughout the 1980s.
Mr Ortega earned fame as a leader of the Sandinista National Liberation Front, which toppled US-backed dictator Anastasio Somoza in 1979. Mr Ortega headed a provisional government, was elected to power and voted out in 1990. He lost two subsequent tries for the presidency.
US ambassador to Nicaragua Paul Trivelli had branded Ortega “a tiger who has not changed his stripes” and claimed a Sandinista victory would lead to “the introduction of a Chavez model” in Nicaragua.
For Sunday’s election Mr Ortega dramatically toned down his revolutionary rhetoric.
He reiterated on Monday that if elected, he would respect private property and said Nicaragua wanted to improve relations with the international community.