* Rebels camped within striking distance of capital
* President refuses demand to step down
* Troops from Chad, other neighbours bolster CAR army (Adds background)
By Jean Rovys Dabany
LIBREVILLE, Jan 9 (Reuters) - Mediators urged Central African Republic's government and rebels to sign a ceasefire on Wednesday as talks got under way to end a month-long revolt, but there was little sign either side was ready to make a deal.
The rebels have come within striking distance of the capital Bangui, posing the biggest threat to President Francois Bozize since he took control of the mineral-rich in a rebellion a decade ago.
"I am asking everyone to show restraint and, in this context, we will suggest at the start of the talks that a ceasefire agreement be signed," said Basile Ikouebe, foreign minister of Congo Republic, which is mediating the talks.
The Seleka rebels are demanding that Bozize step down, accusing him of failing to honour a 2007 peace agreement to give insurgents money and jobs in exchange for laying down their weapons.
Seleka representatives circulated a document at the talks in Gabon's capital, Libreville, saying Bozize should face charges at the International Criminal Court over atrocities allegedly committed during the rebellion that brought him to power.
Bozize did not make an immediate comment but on Tuesday accused the rebels of being foreign gunmen hired by unnamed businesses.
Bozize has relied on foreign military help to fend off a series of smaller insurgencies. Regional powers, chief among them Chad, have sent in hundreds of troops to bolster his army this time.
The Seleka rebels took a string of towns, pushing government forces to within 75 km (45 miles) of Bangui before bowing to international pressure to attend the negotiations in Gabon.
Nine opposition parties attending the talks also demanded the president step down, accusing him of rigging election victories in 2005 and 2011 and isolating the country.
"The resignation of the President Bozize and the establishment of a political transition is a sine qua non condition to end the crisis," the parties said in the joint statement seen by Reuters.
They also demanded the suspension of the constitution and the appointment of a transitional government and national assembly for not more than three years, pending elections.
Bozize has asked to be allowed to complete his mandate, which ends in 2016, and has promised not to seek another term.
"The issue of my departure is out of order. I was twice elected as head of state with more than 70 percent of the vote. I'm here and that's it," Bozize told journalists late on Tuesday in Bangui.
"According to information reaching us, ... among these rebels are Janjaweed (Sudanese militia) and foreigners from neighbouring countries," he said.
CAR's former colonial ruler France used air strikes to defend Bozize in 2006 but has refused his request for military help against the Seleka rebels, saying the days of intervention are over.
Perennial instability has hobbled Central African Republic's chances of securing significant investment from the foreign companies who could exploit its mineral wealth.
France has the biggest mining investment, a uranium mine in the southeast being developed by the nuclear energy group Areva . (Additional reporting Paul-Marin Ngoupana in Bangui and Ange Aboa in Abidjan; Writing by Bate Felix; Editing by Andrew Heavens and Kevin Liffey)