Gambari replaces Adada as head of UNAMID
Mr Gambari is a former Nigerian foreign minister who is currently serving as UN special envoy to Burma.
He will take up his post on 1 January 2010, a spokeswoman for UN chief Ban Ki-moon said.
Mr Gambari replaces Congolese diplomat Rodolphe Adada, who stepped down earlier this year.
Full story: BBC News Gambari to head Darfur UN mission 01:37 GMT, Thursday, 3 December 2009.