- Greatest loss of life in single event in UN history
* 150 peacekeepers, staff unaccounted for after earthquake
* UN says managing relief work, maintaining law and order (Adds briefings by U.N. officials)
By Louis Charbonneau
UNITED NATIONS, Jan 14 (Reuters) - The United Nations said on Thursday that dozens of its personnel were killed in Tuesday's earthquake in Haiti, the worst loss of life the world body has ever suffered in a single incident.
Speaking to reporters via video link from Haiti's capital Port-au-Prince, senior U.N. official David Wimhurst said four U.N. police officials, 13 civilian staff and 19 military personnel were among the dead -- 36 altogether so far.
"Sadly, we must expect ... we will start to recover more bodies," Wimhurst said.
U.N. Secretary-General Ban Ki-moon said earlier that around 150 U.N. staff remained unaccounted for. He added that he had no news about the fate of the head of the peacekeeping mission in Haiti, Hedi Annabi of Tunisia.
Haitian President Rene Preval said on Wednesday that Annabi was dead. But U.N. officials later cast doubt on his remarks, saying they had no information to confirm it.
Annabi was in the five-story U.N. peacekeeping mission's headquarters in Port-au-Prince when it collapsed during the earthquake. U.N. officials said he was among those trapped in the rubble and it was not clear if he was alive or dead.
The U.N. force, which includes about 9,000 troops and police from more than 40 countries, was sent to the country in 2004 to try to bring stability after President Jean-Bertrand Aristide was ousted by armed gangs and former soldiers.
It has supported efforts to bring democracy to Haiti, run programs to disarm militant groups and helped the Haitian police. Haiti has been run by President Rene Preval since May 2006, when it returned to constitutional rule.
Ban and Wimhurst stressed that, along with efforts to rescue its own people, the United Nations was still working to maintain law and order and deliver aid in the poverty-stricken country.
'VERY BADLY AFFECTED'
U.N. humanitarian affairs chief John Holmes said the world body's operations in Haiti "have been very badly affected" by the earthquake and the loss of some of its key personnel, and it was urgently trying to reinforce its ranks.
"That's not happening as fast as we would like," he said.
The U.N. humanitarian coordinator in Haiti, Kim Bolduc, told reporters via the video link that a group of U.N. agencies was taking control of relief efforts in the Caribbean nation and had invited aid organizations to help distribute food, shelter, medicine and other much-needed aid.
Tens of thousands of people are feared dead and many are believed still trapped alive in rubble after the 7.0 magnitude quake hit the capital of the Caribbean nation on Tuesday. [ID:nN13103860]
Holmes said he would launch an appeal on Friday for emergency funds for Haiti, although he did not say how much he would request.
The fate of Haitian nationals employed locally by the United Nations was unknown and was also of concern, Elisabeth Byrs, a Geneva-based spokeswoman for Holmes' Office for the Coordination of Humanitarian Affairs (OCHA), said.
Bomb attacks on the U.N. offices in Algiers in December 2007 killed 17 staff, previously the worst single event for the United Nations in its 65-year history. Fifteen U.N. staff and seven visitors died when a suicide bomber blew up the U.N. headquarters in Baghdad in 2003. (Additional reporting by Stephanie Nebehay in Geneva and Patrick Worsnip at the United Nations, editing by David Storey)