Syrian Deputy Oil Minister Abdo Hussamedin has announced his defection from the government of President Bashar al-Assad.
He is the most senior civilian official to abandon the Syrian Government since the uprising against Mr Assad began a year ago.
He announced his defection in a Youtube video.
An activist who shot the video of Abdo Hussameddin and posted it on YouTube says the opposition helped to arrange the resignation.
The Syrian government has not publicly commented on Mr Hussameddin's announcement.