The Greek stock exchange dropped more than 3.0 percent on Wednesday ahead of an emergency meeting of eurozone finance ministers during which the country will unveil controversial proposals to overhaul its bailout.
The benchmark index was down 3.78 percent shortly after opening amid investor fears that Prime Minister Alexis Tsipras's hardline stance could set Greece on a path leading to its exit from the eurozone.
Tsipras told parliament late Tuesday he would not bow to German demands that his leftist government complete a pending loan agreement with the EU and the IMF before rethinking the terms of the 240 billion euro ($270 billion) bailout that Greece accepted during Europe's debt crisis.
Finance Minister Yanis Varoufakis was in Brussels to present a 10-point plan aimed at securing stop-gap financing that would tide the country over while it negotiates new terms to be put in place from September 1.
In Athens, Tsipras was meeting OECD chief Angel Gurria in a bid to secure support for the proposed reforms, which so far have been cold-shouldered by the EU and paymaster Germany.