FACTBOX: Career of Kofi Annan, Kenya crisis mediator

(Reuters) - Former U.N. Secretary General Kofi Annan is due to arrive in Nairobi late on Tuesday to mediate in the standoff over Kenya's presidential election. Hundreds have been killed in the unrest that followed President Kibaki's disputed re-election last month.

Here are some facts on Kofi Annan:

EARLY LIFE:

* Kofi Atta Annan was born in Kumasi, Ghana on April 8, 1938. He joined the U.N. in 1961 and held dozens of posts before becoming undersecretary-general for peacekeeping operations in March 1993.

CAREER DIPLOMAT:

* As head of U.N. peacekeeping, he presided over its worst moments during the war in Bosnia and the genocide in Rwanda, but was rarely singled out for blame. He commissioned major reports on what went wrong in both countries and apologized on behalf of the United Nations.

U.N. CHIEF:

* In January 1997 Annan became head of the world body and in June 2001, in a sign of his popularity among U.N. member nations, he was re-elected for a second term.

* In 2001 he shared the centenary Nobel Peace Prize with the United Nations for working for "a more peaceful world" by tackling challenges ranging from poverty to terrorism.

* In early 2003, Annan infuriated Washington when he sided with most Security Council members who argued that immediate military action against Iraq was not justified while weapons inspections continued. The invasion began without Council approval in March 2003.

WORST MOMENTS:

* Annan said his worst moments included: being unable to stop the bloodshed in Sudan's Darfur; the oil-for-food debacle; the Iraq war, after which he lost his voice for months.

* His single most painful moment was the bombing of U.N. headquarters in Baghdad on August 19, 2003, killing 22 people, after he had decided, at the urging of the United States, to send senior U.N. staff back to Iraq.

LAST YEAR IN OFFICE:

* In 2006, his last year in office, he regained his confidence, negotiating Israel's withdrawal from Lebanon, rebuking supporters of the Palestinians for tying up the General Assembly with endless resolutions and chastising everyone for lack of action in Darfur.

A NEW LIFE:

* Annan handed over to South Korea's Ban Ki-Moon in January 2007 and said as he returned to Ghana that he was looking forward to spending time with his compatriots.

(Writing by David Cutler, London Editorial Reference Unit)