Although peaceful, Liberia's presidential election has been mired by allegations of fraud [Reuters]

Winston Tubman, Liberia's main opposition candidate, has withdrawn a demand for a recount of the presidential poll and said he will take part in a runoff.

Tubman made his announcement after election authorities declared on Sunday that no candidate had obtained an absolute majority.

A group of nine Liberian opposition parties had earlier asked the West African nation's election commission to recount the votes of the first-round poll, alleging fraud in the results announced so far.

The nine candidates, who include incumbent President Ellen Johnson Sirleaf's two main challengers, said in a statement during a rally that they wanted the National Election Commission (NEC) to release the total number of voters per county and recount all the votes.

The row had threatened to derail Liberia's second post-war ballot, which is a test of progress towards stabilityand its readiness for investment in untapped mineral and agricultural resources.

Latest results announced on Sunday showed that newly named Nobel Peace laureate Johnson Sirleaf was leading with 44 per cent of the votes, ahead of Tubman of the CDC party, on 32.2 per cent with 1,162,729 valid votes and 96 per cent of votes counted.

Despite her lead, Sirleaf remains short of the outright majority required for a first-round win and the NEC's chairman said the election was likely to be decided in a second-round ballot.

"From the statistics we have, we do not think the remaining number will make any difference or give any one party the absolute majority required by law to win on the first ballot," the NEC's James Fromayah told journalists on Sunday.

"Yes, a runoff is imminent," Fromayah said.

A runoff will take place in early November if no candidate secures more than 50 per cent.

Tubman said pressure from the nine political parties had made the NEC reconsider declaring Sirleaf the outright winner in the first-round.

'No evidence of fraud'

"We told them the process was flawed, but now that they are doing the right thing, we will take part in the second round," Tubman told the Reuters news agency late on Sunday after the commission announced the latest results.

"We are confident of victory in the second round," he said. 

The NEC, which had rejected the opposition's allegations of fraud, said turnout stood so far at 71.4 per cent of total registered voters. 

The commission had said the vote would not be tarnished, even if the opposition parties withdrew their officials from the remainder of the counting process, as they had threatened.

International election observers such as the Carter Center, have said they have not seen any evidence of fraud in the election so far.

Around 1.8 million Liberians registered to vote in Liberia's first locally organised poll since an on-and-off 1989-2003 conflict.