Khartoum: Darfur's strongest rebel group threatened yesterday to walk out of new peace talks with Sudan's government if Khartoum pushed on with plans to sign agreements with other insurgents.

The rebel Justice and Equality Movement (JEM), one of the movements that started the Darfur revolt in 2003, signed a ceasefire with Khartoum in Qatar last week promising to come to a final peace deal by March 15.

JEM leader Khalil Ebrahim told Reuters that Khartoum's plans to sign a similar deal with a rebel umbrella group, the Liberation and Justice Movement, would undermine what he saw as JEM's position as the sole negotiator for Darfur's rebels.

Darfur's once highly coordinated rebel movements have fragmented into a mass of often tiny splinter groups, fractured by ethnic divisions and in-fighting between rival commanders.

The disunity has bedevilled successive efforts to resolve the seven-year conflict.

"If the mediation wants multiple agreements ... JEM will be compelled to go out of the mediation and of the host country and to go away," said Ebrahim, speaking by satellite phone.

"To save the peace talks and peace process it is important to unify all movements as one resistance group and to continue negotiations and stop this process of parallel agreements."

Ebrahim said his talks with Khartoum were already on hold. "We have stopped negotiations until we can get assurances there will be no other parallel agreements."