UPDATE 6-Kenya vote count gives Kenyatta chance of outright victory

* Electoral figures show Kenyatta could secure outright win * Odinga's hoping to force a second round * After challenges, electoral body says count credible * Kenyans wary about repeat of post-2007 vote violence (Adds Kenyatta) By George Obulutsa and James Macharia NAIROBI, March 8 (Reuters) - The Kenyan authorities said they would announce a final result on Saturday in a tightly fought election that seemed to put the son of Kenya's founding president, Uhuru Kenyatta, on course for outright victory. Kenyatta, who faces international charges of crimes against humanity, was leading Prime Minister Raila Odinga in the final stages with just over 50 percent of the votes, enough to avoid a run-off if he stays above that level. The Independent Electoral and Boundaries Commission had said it would issue results on Friday, but as its self-imposed deadline approached, an official said an announcement would come on Saturday at around 11 a.m. (0800 GMT). "So please be patient because this is a serious matter," Yusuf Nzibo said, four days after Kenyans turned out in large numbers to vote. "We want to make sure as a commission that our figures are accurate." With results from 18 of the 291 constituencies still to report, Odinga still had a chance to haul back Kenyatta's lead to force a run-off, but it looked increasingly unlikely. At 2125 GMT, 11,689,017 votes had been counted, and Kenyatta, the deputy prime minister, was ahead with 5,862,689 votes, or 50.2 percent, compared with Odinga's 5,065,481 votes, or 43.3 percent, figures displayed by the electoral commission showed. The final outcome could become clear before the formal announcement on Saturday from the electoral commission's regularly updated screen tallying the votes. The poll is seen as a critical test for Kenya, East Africa's largest economy, after its reputation as a stable democracy was damaged by the bloodshed that followed the 2007 election. Much will rest on whether the final result is accepted, and whether any challenges take place in the courts or on the streets. As a victory seemed more likely some of Kenyatta's supporters from his Jubilee coalition were singing and dancing in celebration at a Nairobi venue near the tallying centre where his officials have been delivering statements during the count. If 51-year-old Kenyatta wins, it would pose a dilemma for Kenya's big Western donors because he is due to go on trial at The Hague on charges of crimes against humanity linked to the violent aftermath of the last election in 2007. The count has been questioned by both sides but considered broadly credible so far by international observers. A narrow victory by Kenyatta could prompt legal challenges from Odinga, who also lost in the 2007 election in a disputed vote. WESTERN STATES WARY Both leading candidates, as well as the six others in the race who have made little impact at the polls, pledged before the race to respect the outcome and promised to use only legal channels in the case of any disputes. International observers have said the vote and count have been transparent so far, and the electoral commission has promised a credible vote. The United States and other Western nations, big donors that view Kenya as vital in the regional battle with militant Islam, have already indicated that a victory by Kenyatta would complicate diplomatic relations. Kenyatta, son of Kenya's founding president Jomo Kenyatta, and his running mate, William Ruto, have been charged by the International Criminal Court with unleashing death squads after the 2007 election. Both men deny the charges and have said they plan to clear their names. Turnout has now exceeded 80 percent of the 14.3 million eligible voters, with 273 of the 291 constituencies having reported results. Reflecting how voting tends to run along ethnic lines rather than ideology, constituencies in tribal strongholds of the leading hopefuls often report results that show more than 90 percent or more of votes going to one candidate. Kenyatta, comes from the Kikuyu tribe, Kenya's biggest ethnic community, accounting for about a fifth of Kenya's 40 million people, and Odinga, 68, is a Luo. Their ethnic groups alone could not have secured victory, so both picked running mates from other tribes to beef up their support. CHALLENGES Odinga's camp raised the strongest challenge to the process on Thursday, calling for counting to be stopped, saying it lacked integrity and some results were "doctored," charges that were dismissed by the electoral commission. Even before counting was completed, Chris Mandumandu, a senior official in Odinga's coalition, said the group was considering a legal petition to challenge the count. That marks a change from 2007 when Odinga lost but did not pursue a legal route because he said the judiciary could not be trusted at the time. It has been reformed and made more independent. In Odinga's heartland of Kisumu city in western Kenya, residents gathered in restaurants, bus stations and shopping centres to follow election proceedings on television, anxious to see if their man could take the vote to a second round. "We are hoping to go for a run-off," said businessman Joel Otieno, 42. "I believe Raila stands a better chance in the run-off." Many Kenyans say this vote has been far more transparent. One international observer told Reuters: "I have seen nothing to indicate that the election is not credible." The Kenyan shilling has swayed against the dollar, gaining on reassurances of a smooth counting process and buckling on concerns that delays in announcing a winner would prompt rivals to challenge the election outcome. Analysts said a run-off would unnerve markets by prolonging the uncertainty. Kenyatta's coalition has also complained about delays in the count and challenged the commission over its decision to include rejected votes in calculating the final tally. Rejected votes are running at more than 100,000, potentially impacting any result. (Additional reporting by Yara Bayoumy, Richard Lough, Duncan Miriri in Nairobi and Hezron Ochiel in Kisumu; Writing by Edmund Blair and James Macharia; Editing by Will Waterman)