By Katrina Manson

FREETOWN, Aug 13 (Reuters) - Sierra Leone's opposition took an early lead on Monday as results trickled in from polls that international observers judged broadly transparent.

Saturday's ballot was billed as a test of the West African country's stability after U.N. peacekeepers withdrew two years ago following an 11-year civil war fuelled by "blood diamonds" and infamous for its brutality.

Unofficial results from 10 percent of the country reported by local media showed Ernest Bai Koroma of the opposition All People's Congress (APC) leading the ruling Sierra Leone People's Party's (SLPP) candidate, Vice-President Solomon Berewa.

"The APC has so far about 45 percent of the presidential vote, with SLPP trailing with 35 percent," said Ransford Wright, coordinator of the Independent Radio Network.

He said the People's Movement for Democratic Change, an SLPP breakaway party, had gained 15 percent of the vote.

"PMDC has split the SLPP's vote," said Wright. "It looks like we will definitely get into a runoff."

Full results are expected to take several days. If no presidential candidate wins more than 55 percent, a runoff will be held in September.

Saturday's vote was largely peaceful and foreign observers, who estimated turnout at over 70 percent, were upbeat.

"Election day was well-organised, positive and transparent," European Union mission chief Marie-Anne Isler said on Monday.

"If this continues it will mark a significant and positive development in Sierra Leone's progress towards the consolidation of democracy and peace," she said.

PARTISAN CHIEFS, MEDIA

But the EU's 83 observers also noted several concerns.

"The level playing field amongst contestants was undermined due to the partisanship of some traditional leaders and the dominance and advantages of incumbency enjoyed by the ruling party," Isler said in a preliminary EU observers' statement.

She also noted that state television coverage of the SLPP was "extremely dominant" and stopped short of endorsing the elections until final results are in.

"The period following election day will be crucial to the successful conclusion of these elections," she said. "We call on political parties to respect the results."

President Tejan Kabbah is stepping down as required by the constitution amid popular disillusionment at government graft, which many believe has drained away generous foreign aid.

Sierra Leone ranks second from bottom of the U.N. Human Development Index. The unemployment rate is about 60 percent, most people survive on less than a dollar a day, and the state depends on foreign aid for a third of its budget.

"All the foreign donors who assisted them; their money was not in vain ... It was well-organised and meticulous," said Ken Nnamani, polls observer and former speaker of Nigeria's Senata.

Expectations of change, whoever wins, are huge.

"Most Sierra Leoneans saw this election as a historic moment for their country," said Christopher Fomunyoh, senior associate for Africa at the U.S.-funded National Democratic Institute.

AlertNet news is provided by