Darfur peace talks are due to resume on Friday after a six-month gap that has seen the political and military landscape in Sudan's vast west change in a way that could improve the chances for a deal.
Despite recent infighting which has raised doubts over their ability to form a unified position, rebels may be more willing to negotiate because the government has taken steps to meet demands that stalled past talks.
The African Union says Khartoum has stopped military flights over Darfur and shown restraint in clashes with rebels in the past few months. Government troops have also withdrawn from areas they occupied during a December offensive and handed over to the AU.
For its part, the government may be more inclined to reach a deal because in a rare move in March, the UN Security Council referred Darfur to the International Criminal Court (ICC), which launched a war crimes probe on Monday that is believed to target some government and government-linked militia leaders.
"I would suspect that the government is in a slightly stronger position but the ICC also puts them under more pressure," said Leslie Lefkow, a Sudan researcher at Human Rights Watch.
The top UN envoy in Sudan, Jan Pronk, said with the referral the rebels politically had gained as much as they could. "It's over now...there's no reason anymore to fight, you don't have any reason anymore not to negotiate," Pronk said.
The two rebel groups took up arms in early 2003 accusing the Sudanese government of neglect and discrimination against non-Arabs in Darfur.
Tens of thousands of people have been killed and more than 2 million driven from their homes into teeming refugee camps inside Sudan and across the border in Chad.
The talks to begin on Friday will be the fourth in Abuja. The last round of talks collapsed in December in part because the rebel Sudan Liberation Army (SLA) leadership boycotted talks because of the government offensive, which greatly weakened the insurgents on the ground.