By Kevin Mwanza
NAIROBI (Reuters) - Kenya's defeated presidential contender Raila Odinga has delayed his legal challenge to last week's election result, his allies said on Friday, extending a period of uncertainty over the outcome of the disputed poll.
Odinga refused to accept the slim first-round win by rival Uhuru Kenyatta - and his allies had said he would present a petition to the Supreme Court on Friday alleging collusion between the president-elect and the electoral commission.
But officials from Odinga's CORD coalition told reporters the papers would now go to the court a day later on Saturday - the deadline for complaints - to prevent their challenge getting "mixed up" with other election-related cases.
"The reason for the postponement is merely strategic and has nothing to do with the content of the petition and other accompanying documents," senior CORD member James Orengo said.
Kenyatta, the son of the country's first president, faces charges of crimes against humanity at the International Criminal Court alleging he incited violence during the bloody aftermath to Kenya's 2007 presidential vote. He denies the charges.
There has been no repeat of that elections' deadly tribal violence that sent the region's biggest economy into a tailspin and threatened the country's image as a safe place for tourists and investors.
Odinga has called for calm while he takes his case to court and has said he will accept the final ruling.
While Odinga's petition - and the delay to its filing - will prolong uncertainty about the outcome of the vote, most Kenyans said they were relieved the dispute was being fought out in the courts, not the streets.
"No-one is ready to go back to the streets. We believe the judgement will reflect fairly what happened," said doctor Jack Kataka from Odinga's tribal homeland in the west of Kenya.
Chief Justice Willy Mutunga has promised to deal with any election petitions in a fair, speedy and transparent manner. The court's performance will be seen as a test of ongoing reforms of the judiciary.
Kenyatta only just avoided a second round in last week's poll after winning 50.07 percent of the vote - candidates need more than half of all votes cast to win outright.
But he was more than 800,00 votes ahead of Odinga, who also lost the 2007 election.
In a sign of other looming legal battles, three people with close ties to Kenyatta have filed a petition arguing rejected ballots should not have been included in the final tally, local media reported.
If rejected ballots had been excluded from the final count, Kenyatta would have secured a fractionally more comfortable margin of 50.51 percent of the vote.
International observers said the vote was credible up to the point vote counting started on March 4. But tallying went on for five days, and some observers have not assessed the full process.
Kenyan markets rallied on investor cheer the vote had passed off peacefully. Shares on the benchmark NSE-20 index struck a 4 1/2 year high after the result before easing off slightly in later sessions.
(Additional reporting by Humphrey Malalo and Richard Lough; Writing by Richard Lough; Editing by Edmund Blair and Andrew Heavens)