Share suffered for the third consecutive day, with the main Athens Stock Exchange (ASE) closing down nearly 10 per cent, taking the bourse to its lowest in more than two years.
The ASE was led lower by the banking sector on concerns Greeks were moving cash out of the country. The Bank of Piraeus and the National Bank of Greece closed down 29 per cent and 25 per cent respectively.
At his first cabinet, new Greek prime minister Alexis Tsipras reiterated plans to press ahead with Syriza's campaign pledges, which involves the renegotiation of the country's €240bn (£179bn) bailout.
The new Syriza-led government also said it would halt the planned sale of its 30 per cent stake in the Public Power Corporation of Greece (PPC), the country's biggest port. This sent PPC shares down as much as 14 per cent.
Syriza is the radical leftist party which fell painstakingly short of an overall majority in Greece's general election earlier this week, then forming a coalition government with another anti-austerity party yesterday.
It came to power with a mandate to renegotiate Greece's crippling debt burden, promising reforms such as wage rises and spending cuts while remaining in the euro.