By Kissima Diagana
NOUAKCHOTT, June 22 (Reuters) - For the first time in 59 years of independence, Mauritanians will vote on Saturday for a successor to a democratically-elected president, though a government insider campaigning on a message of continuity is heavily tipped to win.
Polls open at 7 a.m. (0700 GMT) in the election to replace President Mohammed Ould Abdel Aziz, 62, who since seizing power in a 2008 coup has positioned himself as an ally of Western powers in the fight against Islamist militants.
He is stepping aside after serving the maximum two five-year elected terms and has thrown his support behind Mohamed Ould Ghazouani, 62, a former general and defence minister.
Nevertheless, Abdel Aziz could maintain significant influence behind the scenes. He said at a news conference on Thursday that he had not ruled out running again in five years when term limits reset.
Gilles Yabi, the founder of West African think tank WATHI, said Ghazouani was favoured to win the election and would likely continue to rule in Abdel Aziz's mould, but that he could still surprise.
"Ghazouani is someone who is very discreet. It could well happen that the change is not merely cosmetic," Yabi said.
Five other candidates are on the ballot. Former prime minister Sidi Mohamed Ould Boubacar, who is backed by Mauritania's biggest Islamist party, has drawn large crowds on the campaign trail and is considered Ghazouani's main rival.
Ghazouani has campaigned on economic and security progress under Abdel Aziz. The economy is growing and will receive a boost when a large offshore gas field starts producing early next decade.
Tourists, including from former colonial power France, are also starting to return for desert tours after years of staying away due to a series of kidnappings in 2009.
In recent years, Mauritania has been spared attacks by jihadist militants linked to al Qaeda and Islamic State that have devastated other countries in West Africa's Sahel region like neighbouring Mali and Burkina Faso.
Al Qaeda documents seized from Osama bin Laden's Pakistan hideout in 2011 indicated the group's leaders had discussed a possible peace deal the previous year with Mauritania's government that would involve prisoner releases and payments.
Mauritania's government denied that any such deal existed and has credited its success preventing Islamist attacks to intelligence work and rehabilitation of imprisoned jihadists.
The opposition candidates, who include a prominent campaigner against slavery in the country, have tried to tap into dissatisfaction among young people over stagnating salaries and poor health care.
If no candidate receives more than 50% of the vote, the election will go to a second round next month. (Writing By Aaron Ross, Editing by William Maclean)