Syria would be divided into informal zones of regional power influence and Bashar al-Assad would remain president for at least a few years under an outline deal between Russia, Turkey and Iran, sources say. Such a deal, which would allow regional autonomy within a federal structure controlled by Assad's Alawite sect, is in its infancy, subject to change and would need the buy-in of Assad and the rebels and, eventually, the Gulf states and the United States, sources familiar with Russia's thinking say.