* Security Council vote possible by mid-April
* Aim would be to deploy mission ahead of July elections
* France and African allies want 10,000 peacekeepers
* Special rapid-reaction force likely (Adds comment from French defence ministry, Malian presidency)
By John Irish and Michelle Nichols
PARIS/UNITED NATIONS, March 12 (Reuters) - France and its African allies want a heavily-armed force able to counter any resurgent Islamist threat in Mali as part of a United Nations peacekeeping mission, diplomats said.
The United Nations is considering setting up a 10,000-strong force in the former French colony before presidential and legislative elections in July, a deadline a European diplomat described on Tuesday as "a race against time".
U.N. deputy peacekeeping chief Edmond Mulet is in the Malian capital Bamako this week to assess options for a peacekeeping mission once a French-led military intervention that began two months ago is completed.
A heavily armed rapid-reaction force, similar to the unit proposed for a U.N. mission in the Democratic Republic of Congo, would be a departure from its typically more passive peacekeeper operations.
In practical terms, U.N. diplomats say, troops in the rapid-response force would have more freedom to open fire without being required to wait until they are attacked first, a limitation usually placed on U.N. peacekeepers around the world.
U.N. Secretary General Ban Ki-moon is due to deliver a report to the Security Council with peacekeeping recommendations for Mali by the end of the month, and diplomats hope a vote can take place by mid-April.
"The discussion so far in the council shows that a consensus is there (for a peacekeeping mission)," said a senior U.N. official, speaking on condition of anonymity.
Diplomats said the vote hinged on the security situation.
France launched a ground and air operation in January to break Islamist rebels' hold on the northern two-thirds of Mali, saying the militants posed a risk to the security of West Africa and Europe.
French and Chadian troops have been engaged in heavy fighting in northeast Mali, where Islamist militants took refuge, and hope to secure the region by the end of the month.
France's defence ministry said on Tuesday mopping-up operations had been completed in the Adrar des Ifoghas area but they were still searching for remaining Islamist hideouts.
Paris is keen to start, as soon as next month, pulling out some of its 4,000 troops with a view to handing over to the African force, AFISMA, that would later fall under the U.N. mandate.
African leaders say they recognise there will be a French withdrawal but have stressed the need for it to be gradual.
"France will leave once it is possible," Mali's President Dioncounda Traore said during a visit to Senegal. "It is clear that France has pledged to accompany us as long as necessary."
AFISMA comprises about 6,000 troops, mainly from West Africa, including more than 2,000 Chadians. Other than Chad's contingent, most African elements remain in the south of Mali away from the fighting.
"We'd like to see the non-Chadians go north to Gao and Timbuktu so that the focus can be on the final phase in the extreme north," the European diplomat said.
"After that, we're talking about a peacekeeping force of 10,000 soldiers."
RAPID INTERVENTION FORCE
However, there are fears that militants could launch a guerrilla-style insurgency marked by suicide attacks and hit-and-run raids on towns, leaving the U.N. force exposed.
Romano Prodi, the U.N.'s special envoy to the region, said Mali's neighbours also feared contagion.
A rapid-reaction force to counter this threat in Mali could retain battle-hardened Chadian troops, but also include elements from new forces such as Burundi, which has played a key role in fighting Islamists in Somalia.
France's role in that framework has yet to be defined, but diplomats say talks centre on French elements being based either in Mali or elsewhere in the region and intervening if needed.
"It would be under French control, but approved by the United Nations," said the European diplomat.
Financing is also an issue. About $450 million in donations pledged last month to fund African and Malian troop operations has failed to materialise, leaving a burden on AFISMA countries, diplomats said.
Once the Security Council authorises the deployment of a peacekeeping mission - which would take at least two months - the U.N. would equip, finance and support most of the troops and give them human rights training, the U.N. official said. (Additional reporting by Diadie Ba in Dakar; Writing by John Irish; Editing by David Lewis and Andrew Roche)