* Election on Dec. 7
* President Mahama faces seven challengers
* Stakes increased by Ghana's rising oil output
By Kwasi Kpodo
ACCRA, Dec 5 (Reuters) - Ghana's cliff-hanger presidential election on Friday will test the country's reputation as a bulwark for democracy and economic growth in Africa's so-called coup-belt.
The stakes are high with rivals jousting for a chance to oversee a boom in oil revenues that has brought hopes of increased development in a country where the average person makes less than $4 a day.
"Ghana getting it right again will provide real mentorship and a signal for others," Emmanuel Gyimah-Boadi, director of Accra-based consultancy Centre for Democratic Development, said.
Ghana is expected to keep up growth of about 8 percent next year and is increasingly cited by investment bankers and fund managers as an example of Africa's rise in contrast to the woes of Europe and the United States.
President John Dramani Mahama - who replaced the late John Atta Mills after his death from an illness in July - will face top opposition candidate Nana Akufo-Addo of the New Patriotic Party (NPP), and six others.
Opinion polls point to a tight race between the two main candidates, raising the prospect of a repeat of the near deadlock in 2008 elections, in which Mills defeated Akufo-Addo with a margin of fewer than 100,000 votes.
U.S. President Barack Obama called Ghana a "model of democracy in Africa" for stepping back from the brink during those polls, when others might have tipped into conflict.
A disputed election in neighbouring Ivory Coast in 2010 triggered a civil war. Other regional neighbours Mali and Guinea Bissau have been thrown them into chaos by military coups.
Ghana, by contrast, has seen five constitutional transfers of power since its last coup in 1981. The years of peace - along with its rich natural resources - have made it a darling for international investors.
THE SMELL OF MONEY
This election has been coloured by hopes of greater prosperity as output rises from Tullow Oil's offshore Jubilee field, where production began less than two years ago.
Rival billboards in Ghana's sprawling capital, Accra, boil down the campaigns: Nana Akufo-Addo is "The man to trust with Ghana's money". Mahama, meanwhile, is "trusted, decisive and action-driven towards a better Ghana".
"The elections in 2008 were about the smell of oil - now in 2012, it is about the reality of oil," Gyimah-Boadi said.
Tullow's production is expected to rise to 120,000 barrels per day in 2013 from between 60,000 and 90,000 bpd this year while more big deposits have been found.
Akufo-Addo says he would use the oil wealth to pay for free primary and secondary education.
Mahama, meanwhile, says he aims to put Ghana on the path to becoming a middle-income country with a per capita income of $2,300 by 2017 - double that in 2009. He dismisses criticism that the oil industry has created few jobs for Ghanaians.
The World Bank is upbeat on Ghana, expecting growth to be driven by investment in resources, infrastructure and agriculture in a country that also produces cocoa and gold.
But in a country where campaign messages rarely influence voting choices, many believe more than half of the 14 million voters will cast their ballot based on ethnic and social affiliation, or regionalism.
Twenty-seven year old Jacob Djaba, a car-wash attendant in the Osu suburb of Accra, said he and friends would vote for Mahama, "our kinsman". Mahama is from northern Ghana while his National Democratic Congress (NDC) party has also traditionally done well in parts of eastern Ghana.
"He is our own and our thumbs belong to him," Djaba said, to cheers from three colleagues nearby.
Papa Nkansah, a coconut vendor, said he normally voted for the NPP, whose heartland of support is among the Ashanti people with roots in the ancient kingdom of the same name.
"I like Mahama ... but again something tells me I must keep to the Ashanti tradition," Nkansah, 31, said as he rammed a sharp cutlass through a coconut pod at a construction side in Accra's Ridge neighbourhood.
In an effort to smooth over ethnic tensions that have bubbled over into scuffles in recent weeks, presidential candidates signed a peace pact last week. Mass prayers have been organised in churches and mosques.
"There is no doubt Ghana is an icon of political stability on the continent, but there is need to put in place early warning signs against potential electoral violence," head of the national peace council Emmanuel Asante said. (Writing by Richard Valdmanis; Editing by Matthew Tostevin)