BEIRUT/ISTANBUL - Syrian rebel commanders from the Islamic Front which seized control of bases belonging to Western-backed rebels last week are due to hold talks with US officials in Turkey in coming days, rebel and opposition sources said on Saturday.The expected contacts between Washington and the radical fighters reflect the extent to which the Islamic Front alliance has eclipsed the more moderate Free Syrian Army brigades - which Western and Arab powers tried in vain to build into a force able to topple President Bashar Assad.The talks could also decide the future direction of the Islamic Front, which is engaged in a standoff with yet more radical Sunni Muslim fighters from the al-Qaida-linked Islamic State in Iraq and the Levant (ISIL). A rebel fighter with the Islamic Front said he expected the talks in Turkey to discuss whether the United States would help arm the front and assign to it responsibility for maintaining order in the rebel-held areas of northern Syria.He declined to be identified because of the sensitivity of the talks, and gave no further details. Diplomatic sources in Turkey said that US Syria envoy Robert Ford was expected in Istanbul soon but his schedule was not yet confirmed.The Islamic Front, formed by the unification of six major Islamist groups last month, seized control a week ago of weapons stores nominally under the control of the Free Syrian Army's Supreme Military Command (SMC).It has since said it was asked to take over the base by the SMC to protect it from attack by ISIL fighters. Whether or not the move was requested, it demonstrated how little power the Western-backed SMC wields in rebel-held Syria.An SMC rebel commander also said he had been told the Islamic Front would hold talks with US officials in Turkey in the coming days. The infighting and rivalries among the rebels have undermined their fight against Assad in Syria's 2-1/2 year civil war, which has killed more than 125,000 people according to the Syrian Observatory for Human Rights.The conflict has also reduced whole city districts across Syria to rubble, causing tens of billions of dollars of damage, driven 2 million refugees to seek safety abroad and made millions more homeless and vulnerable to a winter storm which has covered the region in snow and biting rain.