A rebel commander in charge of the town of Bukavu in the east of the Democratic Republic of Congo has agreed to drop his key demands, the UN mission said.
Nkunda says he acted to protect the Banyamulenge ethnic group
It said General Laurent Nkunda also agreed to return with his troops back to his home province of North Kivu.
The general had wanted the government to appoint a new army commander in the town captured by his troops last week.
Earlier, there was renewed fighting near Bukavu, but latest reports say the town is now quiet.
The clashes broke out between government forces and rebels, who were supposed to have withdrawn to barracks.
The fighting threatens the 2002 peace deal to end five years of war.
Meanwhile, Belgium's Foreign Minister Louis Michel on Monday mentioned the possibility of European Union peacekeeping troops going to eastern DR Congo.
Mr Michel said in the capital, Kinshasa, that the EU was expected to discuss sending troops later on Monday.
The EU approved a mission to Bunia in June last year - a first military deployment outside Europe.
Gen Nkunda had dropped his demands that the government appoint a new army chief in Bukavu, the UN Mission in Congo, Monuc, said.
The general was also reported to have accepted that the extent of attacks against the Banyamulenge ethnic group had been exaggerated.
He had earlier claimed he took control of the town to protect the Banyamulenge, who are related to Rwandan Tutsis, the BBC's Robert Walker in Bukavu reports.
Monuc also said Gen Nkunda had agreed to withdraw his troops to North Kivu.
But the general failed to honour similar commitments in the past and the UN says it will continue to monitor his withdrawal, our correspondent says.
Meanwhile, the forces of another dissident commander, Colonel Jules Mutebusi, remain in Bukavu and peacekeepers are demanding that they now return to barracks.
But even if government authority is restored in Bukavu, the fall of the town has highlighted the fragility of the peace process and undermined confidence in the UN peacekeeping mission, our correspondent adds.
Gen Nkunda and his allies are members of the largest rebel group, the Rwandan-backed RCD, which controlled all of eastern DR Congo during the five-year war.
The commanders - who are ethnic Banyamulenge - say government forces have been attacking members of their community.
Under the peace deal, all the Congolese warring factions were supposed to unite as a single army, but progress has been slow.
This deal ended five years of war, which left an estimated three million people dead and involved at least five foreign armies.