(Fixes typo in lead)
* Congo Republic president agrees to "accompany" talks
* Short on detail, talks to include politicians and rebels
By Christian Tsoumou and Jonny Hogg
BRAZZAVILLE/KINSHASA, Aug 9 (Reuters) - Democratic Republic of Congo will start talks next week aimed at easing a political standoff in the capital and ending remote rebellions, with the leader of neighbouring Congo Republic taking some form of mediating role.
DRC's last major war ended a decade ago, but localised rebellions, as well as rampant corruption, have hamstrung efforts to rebuild the vast former Belgian colony, a target for billions of dollars of foreign investment.
As well as the "M23" rebellion near the border with Rwanda in the east, and one in the in the Katangan copper belt in the south, political tensions have simmered in the capital Kinshasa, in the west, since President Joseph Kabila's 2011 re-election in a vote the opposition says was riddled by fraud.
Now, the political opposition will take part in talks with the government, rebel groups and civil society, after Congo Republic's president, Denis Sassou Nguesso, agreed to "accompany" the process, although his role and the scope of the discussions are yet to be clarified.
"We came to meet the president to tell him that we will start our dialogue next week," Kengo Wa Dondo, president of DRC's senate, told reporters late on Thursday after meeting Nguesso in Congo Republic's capital, Brazzaville.
A spokesman for the president confirmed he had accepted the role, the exact nature of which will be clarified in further meetings in Kinshasa.
"He is available 24 hours a day. What more can you say?" Wa Dondo said.
The two nation's capitals are separated only by the Congo River but Nguesso's involvement comes after years of strained relations with Kabila.
Problems stemmed mainly from accusations by Kinshasa that Brazzaville was harbouring alleged coup plotters accused of trying to topple Kabila's government.
A visit by Kabila to his counterpart last month to discuss regional politics, including the M23 rebellion, appears to have laid the foundations for Nguesso's involvement.
Kinshasa is already holding talks with the M23 rebels, who briefly seized the eastern city of Goma last year in a major embarrassment to both Congo and a 19,000-strong United Nations peacekeeping mission.
But those negotiations, hosted by Uganda, have stalled and the Congolese army has gained ground in the fighting.
A separate group of rebels carried out an attack in March on Lubumbashi, the capital of the copper mining province of Katanga, which neighbours Zambia in the southeast, exposing Kinshasa's vulnerability to gunmen feeding off local grievances and years of secessionist sentiment.
A beefed-up U.N. force tasked with tackling all rebels in Congo is soon due to be operational but it is not clear who they will target first.
Wa Dondo gave no details on the structure of the talks but confirmed that armed groups would be involved.
Albert Moleka, spokesman for leading opposition politician Etienne Tshisekedi, said that they would welcome Nguesso's mediation in the process but that questions remained over what will be on the agenda.
"There's a link between the problems in the east of the country and the west (Kinshasa), and there's a link between those problems and the badly managed elections of 2011," he said.
"There needs to be facilitation so everyone can agree what the dialogue should discuss." (Writing by David Lewis; Editing by Robin Pomeroy)