* Coalition voted to attend talks by simple majority
* Not clear if influential rebel brigades will back decision
* French foreign minister welcomes decision (Adds detail, quote, French reaction)
By Dasha Afanasieva
SILIVRI, Turkey, Jan 18 (Reuters) - The main Syrian political opposition group in exile, the Syrian National Coalition, said it had agreed on Saturday to attend internationally sponsored peace talks beginning in Switzerland next week.
The "Geneva 2" talks with representatives from President Bashar al-Assad's government start in Montreux on Wednesday and are seen as the most serious international effort yet to end the near three-year conflict.
The splintered Coalition, based in Turkey, has little influence on the ground in Syria, where many rebels oppose the peace talks. Its military arm, the Supreme Military Council (SMC), has been eclipsed by Islamist rebels and al Qaeda-linked fighters.
"It was a tough vote," the head of the Coalition's media office, Khaled Saleh, told Reuters. The Geneva 2 process would be a "political and media battle, and on balance we decided that we must fight it alongside the war on the ground," he added.
It was not immediately clear whether the Coalition's vote would be backed by a separate meeting, in Ankara, of Syrian rebel militias, who would be needed to implement any agreements made at peace talks.
Opposition sources said more than 40 members had withdrawn from the vote because they wanted to wait until fighter representatives arrived in Istanbul from Ankara, to weigh in on the decision.
Out of those that did take part, 58 Syrian National Coalition members voted to attend and 14 voted against, said the group's media office. Another three abstained it added.
The international community had pressed rebels to commit to the talks and French Foreign Minister Laurent Fabius welcomed the coalition's acceptance on Saturday.
"This brave choice despite the provocations and acts of violence by the regime, is a choice to search for a peaceful solution," he said. France, he added, would do all it could to make sure the Geneva 2 talks ended up setting up a transitional Syrian government with full executive powers.
Syrian officials have pledged to attend the January 22 Geneva 2 talks, though they dispute the invitation letter's focus on setting up a transitional authority, saying the priority is "to continue to fight terrorism" - a phrase they use to describe Assad's battle with increasingly radical rebels.
(Additional reporting by John Irish in Paris, Editing by Andrew Heavens)