The Free Syrian Army -- the main armed opposition group in Syria -- came to the agreement Friday after three days of discussions among 260 rebel commanders, The New York Times reported.
The group decided on a 30-person Supreme Military Council, which will be led by Gen. Salim Idriss.
Ahmad al-Qanatri, the commander of a military battalion in northern Idlib Province, said: "The structure is good, but all on condition we get something. I am not sure we will. If we see any rockets and missiles, it will probably be the ones fired at us."
In exchange for unification, the main backers of the rebels -- Qatar and Saudi Arabia -- said they will get money and weapons to rebel fighters through the new military council rather than playing favorites among the groups, commanders said.
"Before, they were always trying to bring different factions to their side, they created divisions, but now they are helping to create unity," said Gen. Abed Farzat, a military commander from Aleppo.