(Adds details on groups at talks, quotes)
By Dasha Afanasieva
SILIVRI, Turkey, Jan 18 (Reuters) - Representatives of major Syrian rebel militias met in Ankara on Saturday to try to agree a common stance on internationally sponsored peace talks, dubbed "Geneva 2", beginning in Switzerland next week, opposition sources said.
Ahmad Al-Jarba, head of the Syrian National Coalition, the main umbrella group of the political opposition in exile, told the SNC's general assembly near Istanbul that the rebels had met, a source in the president's office told Reuters. He declined to be named because of the sensitivity of the talks.
"These groups are not against a political solution," he said, adding that three of four rebels groups had released a statement.
A Coalition member said on condition of anonymity that the statement conveyed a "positive attitude towards a political solution and Geneva 2, but that they have some questions".
One rebel commander had said the powerful Islamic Front was expected to attend the meeting, but another opposition source said the group had not been present at the talks.
Opposition figures say the Islamic Front, an alliance of several Islamist brigades that represent a large portion of the fighters on the ground, is vital for any agreements made at Geneva 2 to be implemented. It has previously said it would consider as a traitor anyone who attended talks that did not bring about President Bashar al-Assad's downfall.
The three rebel groups at the meeting who sent the statement of support for Geneva 2 were the Soldiers of the Levant; the Syrian Revolutionaries Front, which has expressed its backing for the Coalition's Supreme Military Command; and the newly formed Mujahideen Army, an alliance of eight brigades who have accused an al Qaeda affiliate, the Islamic State of Iraq and the Levant, of hijacking their struggle to topple Assad. (Editing by Kevin Liffey)