Leone opposition unite for rerun
The vote was seen as a test of transition to democratic rule
Two opposition candidates in Sierra Leone have formed an alliance for the second round of presidential elections.
With almost all the votes counted, All People's Congress leader Ernest Bai Koroma is in the lead with 44%.
Charles Margai of the PMDC, who has 14% of the vote, says he is now backing Mr Koroma in the second poll since the end of Sierra Leone's civil war in 2002.
The candidate backed by the governing SLPP party, Solomon Berewa, is in second place with about 38%.
President Ahmad Tejan Kabbah is stepping down of serving them maximum two terms.
The BBC's Umaru Fofana in Freetown says the alliance is bad news for Mr Berewa in the run-off due on 6 September.
However members of the PMDC's executive say Mr Margai took the decision by himself and does not speak for the party.
There was a high turnout and the polls were widely praised by observers.
During the campaigns thousands of supporters of the main candidates painted the country in their political party colours in what was a carnival-like atmosphere.
Civil society organisations played an important role touring the country, often dressed in white, promoting non violence.
The previous poll in 2002 was organised by the United Nations, which still had peacekeepers on the ground then.
