By David Lewis and Tiemoko Diallo
BAMAKO (Reuters) - Mali's postwar election produced no clear winner and former Prime Minister Ibrahim Boubacar Keita will face ex-Finance Minister Soumaila Cisse in a run-off due on August 11, the government said on Friday.
Provisional results gave Keita 39 percent of votes cast in the July 28 poll, well ahead of Cisse's 19 percent. But the third and fourth placed candidates may now rally behind Cisse, with whom they have been in coalition.
The election was the first since a March 2012 coup led to the occupation of Mali's north by separatist and Islamist rebels. French forces intervened in January to defeat the al Qaeda-linked Islamists, whose threats to disrupt the poll did not materialize.
The election turnout, at 51.5 percent, was the highest ever in Mali, underscoring its people's deep desire to turn the page on the violence and upheaval that have brought the West African nation to its knees over the last 18 months.
"The crisis is reaching an end ... There will be no problem for the second round," interim Prime Minister Django Sissoko, on a visit to neighboring Ivory Coast, said after the results were announced.
"We are confident that we can do everything to ensure a peaceful vote and a result that will be accepted first of all by the Malian people and also by the candidates," he said.
But more than three million people did not take part and 400,000 of those who did spoiled their ballot papers, according to official figures, setting the stage for some hectic campaigning and coalition building before the second round.
"I think this is a positive thing for Malian democracy given what the country has just gone through," said Christopher Fomunyoh, a senior associate with the U.S.-based National Democratic Institute, which works to strengthen democracy around the world.
"Firstly it allows whoever wins the second round to have a full mandate, legitimacy that is required to govern. Secondly it is going to allow the election management body... to address some of the shortcomings that were identified in the first round," he added.
Fears of a chaotic poll were not borne out and voting was largely orderly, though some voters struggled to find their names on voter lists and voting in refugee camps, embassies abroad and the northern region of Kidal was disrupted.
France dispatched thousands of troops to Mali in January to halt an Islamist advance southwards, and the pace of their withdrawal hinges on a successful vote.
A 12,600-strong United Nations peacekeeping mission is rolling out and will prop up security as Mali reforms its army and looks to complete negotiations with Tuareg separatist MNLA rebels, who allowed the vote to take place but are still armed.
The mood at Keita's campaign headquarters was muted after their hopes of a first-round win had been raised when he built a strong early lead.
"I was counting on the victory of my candidate Ibrahim Boubacar Keita in the first round," said Aziz Ould Mohammed, a doctor. "I'm very disappointed, but this is part of the democratic game."
"Don't despair," Abdoulaye Maiga, Keita's campaign director, told a group of supporters. "All we need to do now is bridge the small gap that separates us from victory."
Amadou Koita, a spokesman for Cisse, who had threatened to challenge the results if there was no second round, said parties allied to the runner-up had scored more than 15 percent, putting the coalition within reach of Keita.
Mali's Constitutional Court must confirm the provisional results before the second-round vote can go ahead. Turnout in Mali's previous elections had never hit the 40 percent mark.
(Additional reporting by Adama Diarra in Bamako and Ange Aboa in Abidjan; Writing by David Lewis and Bate Felix; Editing by Joe Bavier and Alistair Lyon)