By Kwasi Kpodo
ACCRA (Reuters) - Ghana's opposition leader John Atta Mills won a last run-off vote and was declared president-elect on Saturday, sweeping his party back to power after eight years.
Results of voting in a final constituency on Friday showed Mills, of the National Democratic Congress (NDC), narrowly defeated Nana Akufo-Addo of the ruling New Patriotic Party (NPP). The NPP lost its parliamentary majority last month.
"I want to assure everybody that I will be president for all. There will be no discrimination," Mills said in a victory speech to thousands of NDC supporters who thronged the streets around his office in the capital Accra.
The poll, one of the closest leadership elections in Africa, has raised tensions in the gold- and cocoa-exporting country whose political stability has attracted growing numbers of foreign investors as it prepares to produce oil in late 2010.
Legal challenges and accusations of violence by both main parties had threatened to mar a vote seen as a chance to bolster Africa's battered democratic credentials after flawed and bloody polls in Zimbabwe and Kenya. Mills took a conciliatory tone.
"I would want to congratulate all other contestants, especially Nana Akufo-Addo, for giving us a good fight. It is my hope that we will be able to work together to build a better Ghana," he said. Then an aide popped open a bottle of champagne.
There was no immediate reaction from Akufo-Addo's camp. International monitors say voting has been mostly peaceful.
Announcing the results at a news conference in the capital Accra, Electoral Commission Chairman Kwadwo Afari-Gyan said turnout in the run-off vote, which was held in most of the country on December 28, was 72.91 percent.
Mills won 50.23 percent of the votes against 49.77 percent for Akufo-Addo, whose party had no immediate comment.
Neither candidate won a majority in the original December 7 poll and run-off voting in all but one of the West African country's 230 constituencies last Sunday was inconclusive, so the election was decided by Friday's voting in the farming constituency of Tain.
FROM RULING PARTY TO LOSING PARTY
The NPP, which lost its parliamentary majority in the December 7 poll but remains in power until President John Kufuor steps down on January 7, boycotted the Tain vote over security concerns but failed to prevent the poll taking place.
Outside Mills's office, a woman dragged an effigy of an elephant -- the NPP's campaign mascot -- in a mock funeral as other NDC supporters chanted "Elephants, go back to the bush!."
"You have cause to celebrate, but let's not do anything to provoke disunity. We must know that this is only one day in a journey of a million miles," Mills told his supporters.
Each side has accused the other's activists of violence and irregularities and appealed to the electoral commission to review some of the results from last Sunday's vote.
Afari-Gyan said the commission had found no evidence to call the results into question and declared Mills president-elect.
"I think there is demand for change ... power outages and corruption in the NPP have really been the key issues for people, "Kissy Agyeman, Africa analyst at London-based consultancy Global Insight, told Reuters before the result was announced.
The centre-left NDC has promised change after eight years of NPP rule, though analysts say there are few policy differences.
Kufuor was voted to power when Mills's NDC ally, former coup leader Jerry Rawlings, gave up power in early 2000 as required by the constitution which his own administration had introduced.
Kufuor's pro-market rule has seen Ghana's economy become one of the most attractive investment destinations in the region.
But critics say his administration has failed to tackle widespread corruption, including smuggling of cocaine and other drugs in which administration officials have been implicated.
