* Paris plans to send 3,000 to fight Islamists
* Delayed to concentrate on new fighting in north Mali
* France fears militants could mount wider attacks (Adds U.N. meeting, French troops to Kidal)
By John Irish and Marine Pennetier
PARIS, May 20 (Reuters) - France has delayed plans to redeploy 3,000 soldiers to fight militants across Africa's Sahel region, saying it first needs to help deal with a new outbreak of violence in northern Mali.
Paris had hoped to move the troops from its former colony Mali and other bases to target Islamist groups operating between southern Libya, northern Chad and northern Niger. It fears the fighters could use the region as a base for wider attacks.
But it paused the plans after deadly clashes broke out between Mali government troops and Tuareg MNLA separatists in the northern town of Kidal over the weekend, officials said.
"Given the events of the last 48 hours, the operation to transfer operation Serval (in Mali) to a Sahel-Sahara French force must be delayed for several weeks," a Defence Ministry source said on Tuesday.
France originally sent troops into Mali after al Qaeda-linked Islamists took advantage of a Tuareg-led rebellion and seized control of the country's north in 2012.
After that intervention drove the Islamists from major cities and towns, Mali's government and separatist groups signed a deal to hold talks about greater autonomy for the north, but little progress has been made since last year with tensions gradually rising.
A French military source said no new date had been set for the broader West African deployment, originally scheduled to be completed by the end of May.
At least eight Malian soldiers and eight civilians including six government officials were killed when rebels attacked the regional governor's office in Kidal on Saturday.
The army retook key positions in the town, the traditional stronghold of the MNLA, on Tuesday without fighting but rebels remain in control of a military camp and the governor's office, a military source and a witness said.
"All the (army) reinforcements have arrived and they have taken control of all the strategic positions in the town except the governor's office. We are just waiting for a political decision before moving onto the offensive," a senior military source told Reuters.
The French army, which has about 1,600 troops based in the country, said it now had about 90 soldiers in Kidal having sent an extra 30 as a precautionary measure.
Defence Minister Jean-Yves Le Drian postponed a May 25 trip to Mali and Chad, where the new broader operation will be based.
He had planned to outline details of the mission that would operate across the Sahel region along the southern edge of the Sahara Desert, to fight Islamist militancy.
"There is an urgency in the coming days to restore calm in Kidal, because this must not derail the reconciliation process," a French diplomatic source said.
Highlighting Paris' concerns it called for a U.N. Security Council meeting to discuss Mali later on Tuesday.
MINUSMA, the U.N. peacekeeping mission in the country, is still not at its full strength of 13,000 and, while it was present in Kidal on Saturday it was unable to stop the fighting.
After winning adulation across Mali for its 5-month military offensive, France has been caught in the middle of a diplomatic tussle between the government wanting to assert its control and the rebels still demanding some form of autonomy in the north.
Both have accused Paris, the former colonial power, of not doing enough to promote their cause and of supporting the other.
"The situation could deteriorate but not to the extent of 2012, mostly because of the presence of foreign troops," said Jean-Baptiste Bouzard, Africa analyst at risk consultancy Maplecroft.
"At the moment, they (the French) have decided to stay neutral but if France decides that the situation can't worsen anymore, its army has the capacity to put an end to MNLA action," he added. (Additional reporting by Tiemoko Diallo in Bamako and Emma Farge in Dakar; Editing by Alison Williams)