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 refuses to accept the slim first-round win by Kenya's richest man, 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 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.
So far there, has been none of the fatal tribal violence that erupted after the disputed 2007 presidential election, but hundreds of students protested on Friday at a Nairobi university after discovering voting material on campus.
Kenyatta, son of the country's first president, faces charges of crimes against humanity at the International Criminal Court alleging he incited the 2007 violence. He denies the charges.
Those clashes 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.
However, the students at Kenyatta University - named after the president-elect's father - stormed the campus grounds on Friday evening after discovering unattended boxes containing voting slips from the March 4 election, Kenyan media reported.
Media said the students believed politicians had planned to use the votes to rig the election. It was not clear whether the ballot papers had been used.
Television pictures showed students waving voting slips for the cameras, as well as stacked cardboard boxes with the green logo of Kenya's Independent Electoral and Boundaries Commission (IEBC) inside campus buildings.
Images on different television stations appeared to show opened, empty plastic ballot boxes as well. The students were shown peering into a room marked with an "out of bounds" notice, where the boxes were stored.
The IEBC was not immediately available for comment.
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, for the most part, on the streets.
"No one is ready to go back to the streets. We believe the judgment 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 election petitions in a speedy and transparent manner. The court's performance will be seen as a test of reforms of the judiciary.
Kenyatta comfortably beat Odinga in terms of votes won, 50.07 percent versus 43.28 percent, but only narrowly avoided a run-off after winning just 8,100 votes more than the 50 percent needed to be declared the winner outright.
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, Drazen Jorgic; Editing by Edmund Blair and Alison Williams)