Jan 27 (Reuters) - Sudan will hold its first democratic elections in 24 years in April and nominations closed on Wednesday.
In the presidential vote, if no single candidate wins more than 51 percent of the vote, the top two will go head-to-head in a second round.
More than a dozen candidates are likely to stand, all Muslim with one woman and one southerner among the contenders, the elections commission says.
Here are profiles of some of the leading candidates:
YASIR ARMAN - SUDAN PEOPLE'S LIBERATION MOVEMENT
Arman is a northern Muslim who joined the former southern rebel Sudan People's Liberation Movement (SPLM) 24 years ago.
He says his nomination proves the SPLM is a truly national party, and has vowed to win the votes of the millions of marginalised in Sudan, push through democratic reforms and prioritise development.
Some analysts say the SPLM's decision to nominate him, rather than party leader Salva Kiir, implies they are more interested in consolidating their position in the south than in winning the national poll.
Kiir is running in the separate poll for president of southern Sudan which is due to vote on independence in 2011.
Arman, 49, whose father is from the same Ja'aliy tribe as President Omar Hassan al-Bashir, has been vilified by the NCP.
As the head of the SPLM parliamentary group, he advocated that sharia not be applied to non-Muslims and pro-NCP Islamist scholars issued a fatwa implying Arman was an apostate, a crime punishable by death.
He is married to a Christian Dinka from Abyei and has two daughters. Arman was nominated with more than 56,000 supporting signatures for the presidency.
OMAR HASSAN AL-BASHIR - NATIONAL CONGRESS PARTY
Sudan's 74-year-old president is also a wanted man, with an arrest warrant hanging over his head from the International Criminal Court (ICC) over alleged war crimes in Darfur.
If anything, Bashir's defiance of the warrant, and implicitly of the West, has enhanced his appeal among parts of the northern electorate.
That, combined with the domination of the army, the security services and state media by his National Congress Party (NCP) has led many to see him as the favourite in the presidential race.
Bashir was an obscure army brigadier when he came to power in a bloodless coup in 1989 in an alliance with Islamists, deposing the country's last elected civilian government.
In the early years of his rule, he oversaw Sudan's transformation into a radical Islamic pariah state and provided a refuge for al Qaeda leader Osama Bin Laden and Carlos the Jackal.
In 2005, he brought his country closer to the international fold with a peace deal that ended more than two decades of north-south civil war.
That progress was overshadowed by a revolt in Darfur.
Colleagues describe Bashir as a back-seat leader who rallies crowds with populist rhetoric, often followed by a jig.
Bashir has promised to resolve the Darfur conflict through negotiations and to enhance relations with the south, even if it chooses secession in a 2011 referendum. He was nominated with 31,000 signatures.
SADEQ AL-MAHDI - UMMA PARTY
The head of the Umma party is revered by a large part of Sudan's northern population as a spiritual leader and a descendent of the self-proclaimed Mahdi, a visionary figure who fought the British in the 19th century.
In the elections, Mahdi will play on his democratic credentials as Sudan's last elected civilian prime minister and on the large support for his party's associated Islamic sect, the Ansar.
Oxford educated, he served as prime minister twice until he was overthrown by Bashir in 1989. His party has suffered splits since his return from exile in 2000.
The Umma traditionally enjoyed mass support in Darfur. Many surmise a revolt which shattered the tribal administration could affect their influence there during the vote.
Late last year, he was one of the driving forces behind a loose alliance between more than 20 parties, including the SPLM, the Communists and the Popular Congress Party (PCP).
The "Juba Alliance", which called for democratic and financial reforms, has since shown signs of faltering. Its members have hinted they would rally behind a single candidate against Bashir if there is a second round of the presidential poll.
He was nominated with about 34,000 signatures.
ABDALLAH DENG NHIAL - POPULAR CONGRESS PARTY
Nhial is a south Sudanese Muslim who was part of Bashir's government before Islamist ideologue Hassan al-Turabi lost a bitter leadership battle in 1999/2000 and split to form his opposition Popular Congress Party (PCP).
PCP leader Turabi, who has spent years in jail or under house arrest since his rift with Bashir, said he wanted to show the PCP was a national party with no regard for race or ethnicity with the choice of Nhial to run for president.
From the largest southern Sudanese tribe, the Dinka, the 56-year-old is a relative of the late SPLM leader John Garang.
From a humble background in the deep south, he wants to reduce poverty by prioritising education, health and sanitation, and stamp out on corruption.
He hopes that as the first south Sudanese president -- he is the only southern candidate -- he will encourage southerners to vote for unity in a 2011 referendum on independence.
From a multi-faith family of Christians, Muslims and traditional religions, he said his party would not enforce Islamic law on the south.
Nhial is an Arabic teacher and graduated from al-Azhar University in Cairo. He was minister of religious endowments, youth and sport, minister of peace and a parliamentary whip during his 10 years of government.
He was nominated with more than 26,000 supporting signatures.
HATIM AL-SIR - DEMOCRATIC UNIONIST PARTY
The Democratic Unionist Party (DUP) is a sectarian party, considered to be one of the largest parties in north Sudan enjoying mass support from Muslims affiliated with the religious Khatmiyya sect.
In the last democratic elections in 1986, the DUP formed a coalition government with Mahdi and held the post of president, at that time a less influential position.
Spokesman for the DUP, al-Sir is a distant relative of the powerful al-Merghani family who lead the party. He grew up in the family home in Khartoum before leaving to follow the party's religious leader Mohamed Osman al-Merghani into exile in 1989.
The Khatmiyya believe the al-Merghanis are descendents of the Prophet Mohammad.
After moving between Egypt, Eritrea and Saudi Arabia, al-Sir returned to Sudan only last year for the funeral of Mohamed's brother, former President Ahmed Osman al-Merghani.
Observers say Al-Sir is trusted implicitly by the party powerhouse Mohamed Osman al-Merghani who prefers to lead from "behind the scenes".
Despite the party having split many times, DUP leader al-Merghani still commands a major following. He was nominated with more than 44,000 signatures. (Reporting by Opheera McDoom and Andrew Heavens; editing by Andrew Dobbie)