By Joseph Guyler Delva and Pascal Fletcher
PORT-AU-PRINCE (Reuters) - Voting in Haiti's presidential run-off started slowly in some places on Sunday, with foreign donors hoping the poll would produce the stability needed to rebuild the earthquake-crippled nation.
In the wrecked capital Port-au-Prince, several polling stations were unable to open on time because materials such as ink to mark voters' fingers and labels to mark the urns had not arrived, witnesses said. Arguments also broke out over which officials and party representatives should be there.
As groups of Haitians waited to vote, polling officials scrambled to get the stations ready. Blue-helmeted Brazilian U.N. troops guarded voting centers along with Haitian police, and white U.N. armored vehicles rumbled through the streets, many still strewn with debris left from last year's quake.
The election presents Haiti's 4.7 million voters with a choice between a political newcomer, energetic entertainer and singer Michel Martelly, 50, and former first lady Mirlande Manigat, 70, a law professor and opposition matriarch.
The run-off followed a chaotic first round vote on November 28 that dissolved quickly into fraud allegations and unrest.
The United Nations, which is supporting the election, says voting improvements have been made that should better ensure a clear, credible outcome for the run-off in one of the world's poorest and most disaster-prone states.
"I need a president to change the situation of the country," said Adeline Hyppolite, 50, a small trader, who cast her ballot in the Petionville district of the capital.
"We are hoping for a better life ... but only God knows. We hope we'll find the change we're looking for," she added, saying her husband had been disabled in the quake.
The Caribbean state desperately needs a capable leadership and government to steer a post-quake reconstruction that requires billions of dollars of foreign assistance.
"This is the first time in Haitian history that they will have a run-off election, a second round, so I think the product of this election will be a legitimate one that will have the support of the majority of the Haitian people and that alone is already an asset for the next government," Edmond Mulet, the U.N.'s top official in Haiti, told Reuters.
U.N. Secretary-General Ban Ki-moon and other international leaders appealed for a calm, transparent vote.
ARISTIDE PRESENCE HANGS OVER POLLS
Weighing on many Haitians' minds as they cast their ballots will be the reappearance of a political heavyweight from the past, former President Jean-Bertrand Aristide, who arrived back from exile on Friday.
The return of the charismatic left-wing populist and former Catholic priest who still commands a big following in Haiti was opposed by the United States and United Nations as potentially disruptive to the polls. But Aristide is not a candidate and aides have said he will stay out of politics.
Although Aristide, who was driven into exile by a 2004 rebellion, has not clearly endorsed any candidate, many voters have been trying to interpret who he favors in what is expected to be a close-fought run-off. Nevertheless, recent opinion polls have shown Martelly slightly ahead of Manigat.
Mixed in with banners welcoming Aristide, the dueling slogans of the rival candidates were plastered on walls.
Martelly's "Tet Kale" slogan, a Creole play on words that refers to his shaven head and also means "all the way" to convey his promise of forceful change, contrasts with Manigat's more homely "Banm Manman'm" (Give me Mummy) slogan that seeks to bolster her image of experience and responsibility.
Reflecting ex-president Aristide's enduring image as a champion of the poor, many Haitians said that if he were on the ballot they would vote for him.
Under Haiti's election law, the Provisional Electoral Council is due to announce preliminary results from the run-off on March 31, with final results being confirmed on April 16.
The U.N.'s Mulet acknowledged this long wait for results ran the risk of rival camps stirring up supporters with noisy claims of victory or fraud -- such claims in the first round triggered street protests. But he was confident U.N. forces supporting Haiti's police could control the situation.
(Editing by Paul Simao)