Uncertainty spurs sell-off in Greek stock markets, borrowing rates rise further

Uncertainty over the government's survival and future of Greece's bailout program has spurred a second day of heavy selling on the Athens Stock Exchange, with the main index down a massive 9.4 percent.

Wednesday's plunge follows a loss of 5.7 percent the previous day. Yields on Greece's 10-year bonds also rose sharply, to above 7 percent.

The losses come amid a wider drop in markets, but were exacerbated by a survey on Monday showing the opposition anti-bailout Syriza party had a lead over the governing party. That means the government could face an early election in February if the opposition lawmakers fail to back a candidate for the country's new president.

Conservative Prime Minister Antonis Samaras was to chair a cabinet meeting on the economy later in the day.