Darfur rebels, army clash in Sudan oil region

* Rebels say fight off ambush in neighbouring Kordofan

* Possible sign of new insurgent push outside Darfur

* Tribal leader confirms clash, says army victorious

By Andrew Heavens

KHARTOUM, Aug 3 (Reuters) - Darfur rebels said on Monday they clashed with Sudan's army in the neighbouring oil-producing region of Southern Kordofan, the latest sign of insurgent efforts to spread their struggle to other parts of Sudan.

The rebel Justice and Equality Movement (JEM) said its forces fought off an army ambush around midday on Sunday close to the town of Babanusa, leaving an unknown number dead.

A leading member of the area's dominant Arab Misseriya tribe confirmed there had been a clash, but said government forces had prevailed and now controlled the area.

No one was available to comment from Sudan's armed forces.

The Sudanese authorities will be concerned by any sign of a new JEM push from Darfur into Kordofan, a region with many of the ethnic tensions and grievances over perceived government neglect that sparked the six-year Darfur conflict.

The fighting is the first confirmed clash between JEM and Sudan government ground forces in more than two months.

JEM was due to re-start troubled discussions with Sudan's government this month, designed to pave the way to peace talks. U.N. and African Union mediators are also trying to pull other insurgent forces into negotiations.

JEM leader Khalil Ibrahim told Reuters by satellite phone that a large JEM force had been travelling through the area, visiting what he described as JEM garrisons, when it was attacked.

"My army was on an administrative mission when they were ambushed by the Sudanese army. We destroyed many of their vehicles and killed many of them," he said.

Ibrahim said his force was visiting established JEM positions in Southern Kordofan, manned by local recruits.

"JEM is trans-national movement, not just a movement for Darfur. We fight for marginalised people and the people of Kordofan are also marginalised."

A Misseriya official, speaking on condition of anonymity, said there were no substantial JEM positions in the region.

"There have been small groups of JEM moving around in this area. There was a fight between government troops and JEM. The situation is now under the control of the government."

U.N. sources said there had been reports of government Antonov aircraft bombing a force of armed men near Haskanita, a North Darfur settlement close to the Kordofan border, two days earlier on Friday.

JEM was one of two main rebel forces that took up arms against Sudan's government in 2003, demanding better representation for the region and accusing Khartoum of neglecting its development.

Khartoum mobilised mostly Arab militias to crush the uprising, unleashing a campaign that Washington and activists describe as genocide. Sudan's government denies the charge and accuses the Western media of exaggerating the conflict.

Estimates of the death count range from 10,000, according to Khartoum, to 300,000, according to the United Nations.

JEM, which has clashed with the army before in Kordofan, says it is fighting for a fairer system of government across Sudan. Its forces, which Sudan says are backed by neighbouring Chad, attacked the Khartoum suburb of Omdurman in May 2008. (Additional reporting by Khaled Abdel Aziz in Khartoum; Editing by Giles Elgood)