BAMAKO, Sept 18 (Reuters) - A company of about 150 Chadian soldiers of the United Nations peacekeeping force in northern Mali abandoned their posts on Wednesday in protest at the length of time they have served, a spokeswoman for the U.N. mission said.
The soldiers, who fought alongside French forces to oust Islamist militants who had occupied northern Mali, have been in the arid region for several months and are demanding that their rotation be speeded up, Samantha Buonvino said.
"About 150 of them left Tessalit for Gao," Buonvino said by telephone from Mali's capital Bamako, referring to the town the troops had been stationed in.
She said the U.N. mission in Mali (MINUSMA) and Chadian military authorities were in discussion with the troops to seek a solution to their grievances, adding some troops remained in Tessalit and the mission had taken measures to continue securing the northern town.
About 2,000 troops from Chad took part in the ground offensive to defeat an Islamist rebellion in northern Mali and 38 were killed in combat. The United Nations took over command of the African peacekeeping force in Mali in July.
The force, which includes troops from several African nations including Chad, Niger, Senegal, Nigeria and Burkina Faso, is the United Nations' third largest, expected to number about 12,600 soldiers and police officers once fully deployed.
Ibrahim Boubacar Keita, Mali's new president, was sworn in on Sept. 4. An official ceremony to mark the event will be held in Bamako on Thursday, attended by several heads of state including French President Francois Hollande. (Reporting by Bate Felix; Editing by Janet Lawrence)