Syrian expatriate organizations from 15 European countries declared themselves in opposition to President
Bashar al-Assad on Saturday and formed a joint movement in Vienna, DPA reported.
The new Union of Syrians Abroad called for the "toppling of the Syrian regime and for the creation of a democratic multi-party state" while stressing the principle of non-violence and its opposition to foreign military intervention.
It also called on Syrian embassies to distance themselves from the current government, Austrian broadcaster ORF reported.
The Union plans to support opposition members in Syria and those who flee abroad.
It represents expatriates in Austria, Britain, Czech Republic, Germany, Greece, Hungary, Italy, Moldova, Poland, Romania, Russia, Slovakia, Spain, Switzerland and Ukraine.
Late last month, some opposition activists founded a National Transitional Council in Turkey, modelled on the one formed by Libyan rebels.
Protests calling for political reforms began in mid-March and developed into calls for the ouster of al-Assad.
The United Nations has estimated that more than 2,200 civilians have been killed in the government's violent crackdown.