By James Macharia
NAIROBI, March 1 (Reuters) - Kenya holds a presidential election on March 4, the first since a disputed 2007 vote that triggered politically-instigated ethnic killing across the nation and left at least 1,220 dead.
The bloodbath damaged the image of the east African country of 40 million people, the region's biggest economy and a key ally in the U.S.-led war against militant Islam in the region.
The vote will be keenly followed by the international community to see if Kenya can rebuild its credentials as one of Africa's most stable democracies after it adopted a new constitution in 2010 to allow for freer elections.
President Mwai Kibaki is barred by law from seeking a third five-year term and the two top contenders to replace him, Prime Minister Raila Odinga and Deputy Prime Minister Uhuru Kenyatta, are running neck-and-neck in polls but well ahead of six others.
To win outright, a candidate needs more than 50 percent of the votes cast by the 14 million eligible voters, or it goes to a run-off between the top two on April 11. That date could slip depending on any legal challenges after the first round.
Provisional results could emerge hours after polling stations close, helped by a new electronic tallying system. But an official announcement may not come for days, though it must be released no later than a week after the vote.
Alongside the presidential election, voters will also choose senators, county governors, members of parliament, civic leaders and women county representatives.
THE LEADING CANDIDATES
* PRIME MINISTER RAILA ODINGA
The 68-year-old prime minister who lost to Kibaki in 2007 has joined forces with former rival, Vice President Kalonzo Musyoka, to form the Coalition for Reform and Democracy (CORD).
Odinga is known for regaling crowds with traditional riddles and commands a cult-like following among his Luo tribe which hails from the west of the country near Lake Victoria.
Odinga, known as "Agwambo" which means controversial or daring, is the strongest challenger to the bloc that has dominated politics since independence in 1963, made up predominantly of members of Kenyatta's Kikuyu tribe.
With a father who was a major figure in post-independence politics, Odinga raised eyebrows when he revealed in a biography he had been a plotter in a 1982 failed coup attempt.
Odinga projects himself as a reformer and champion of the poor, but he part of a rich elite with interests in oil, a liquid petroleum gas cylinder maker and a molasses factory producing ethanol for export.
Odinga's constituency includes Nairobi's Kibera slum, one of Africa's largest and a haven for bandits. Critics say he has done little to fight poverty in Kibera, where many residents are Luo. But that is unlikely to deter his Luo backers or members of Musyoka's Kamba tribe who are expected to line up behind him.
* DEPUTY PRIME MINISTER UHURU KENYATTA
Kenyatta, 51, son of the Kenya's founding President Jomo Kenyatta, was first thrust onto the political stage as the preferred successor to former President Daniel Arap Moi in the 2002 vote, which he lost to Kibaki. Kenyatta then sided with Kibaki in the 2007 election.
Backed by Kikuyu loyalists, Deputy Prime Minister Kenyatta has picked a running mate from the rival Kalenjin tribe, William Ruto, to form the Jubilee alliance. Both have been indicted by the International Criminal Court to face charges of orchestrating violence after the 2007 vote, an accusation they deny.
Five years ago, the two men backed opposing presidential candidates and their two rival tribes were at the centre of the fierce blood-letting that drove 350,000 people from their homes.
Kenyatta quit as finance minister after he was indicted and has fended off jibes from Odinga that he would have to run the presidency by Skype from The Hague if he won.
Cautions from the United States and other Western nations that Kenyans should choose their president carefully do not appear to have harmed him at the polls and may have given him a boost among those who see such remarks as colonial intervention.
His trial is not expected to start until August.
Kenyatta, ranked by Forbes as the richest man in Kenya, is heir to his late father's vast business empire that spans swathes of land, Kenya's biggest dairy company, five-star hotels, banks and exclusive schools. Even when pressed in a presidential debate, he was reluctant to reveal exactly how much territory his family owned.
* DEPUTY PRIME MINISTER MUSALIA MUDAVADI
Though well behind the two main contenders, the 53-year-old Mudavadi could become "king-maker" by swinging his supporters behind either Odinga or Kenyatta should there be run-off.
A former deputy in Odinga's ODM party, the two parted ways after a row over how to run the party primaries to select candidates. Mudavadi was then courted by Kenyatta to lead the Jubilee coalition but, under pressure from his Kikuyu backers, Kenyatta ditched the idea and two had an acrimonious falling out.
Mudavadi, who like his rivals hails from a political family, now heads the Peace coalition that is mainly backed by members of his Luhya tribe, Kenya's second biggest behind the Kikuyu. However, some Luhya have already lined up behind Odinga. (Reporting by James Macharia; Editing by Edmund Blair and Andrew Heavens)