The Iraqi wing of al-Qaeda has announced that rebel group al-Nusra Front,which is at the forefront of the Syria rebellion, is a branch of al-Qaeda.
SITE Intelligence Group claims that both groups would operate under one name.
The leader of the Islamic State in Iraq, Abu Bakr al-Baghdadi, said his group and Syria's al-Nusra Front would now jointly go under the name of the Islamic State in Iraq and the Levant.
The predominant Islamist element in the Syrian uprising has created concern for regional and Western powers and deepened the Shia-Sunni divide in the Middle East.
The authenticity of the statement could not be verified.
If confirmed it is likely to further deepen the political dilemma facing those countries who oppose Syrian President Bashar al-Assad but fear the rise of al-Qaeda and Islamist militancy in Syria.
Experts have long said that al-Nusra Front was receiving support from al-Qaeda-linked insurgents in neighbouring Iraq.
The group has claimed responsibility for deadly bombings in Damascus and Aleppo, and its fighters have joined other rebel brigades in attacks on Mr Assad's forces.
At least 70,000 people have been killed since protests led by Syria's Sunni Muslim majority broke out two years ago.
The demonstrations were met with bullets, sparking a Sunni backlash and a mostly Islamist armed insurgency increasingly led by the al-Nusra Front.
