Greek stocks plummet after election announcement

Greek shares suffered one of their worst hammerings in decades Tuesday, after the government announced it will bring presidential elections forward.

Prices on the Athens stock exchange plunged over 11% on Tuesday, the day after Prime Minister Antonis Samaras made the announcement.

The Athens benchmark index was on course to suffer the biggest one-day drop since 1987. Bonds also suffered, with the 10-year yield rising 0.49 percentage points to 7.63%, a sign of investor wariness.

Investors fear the main left-wing opposition party, Syriza, which is leading in the polls, might win Greece's next general election. Syriza said it would demand a substantial cut to what Greece owes in bailout loans.

Greece has been relying on 240 billion euros ($294 billion) in loans from the European Union and International Monetary Fund since 2010. The bulk of the loans program — from the EU — runs out this year, although European finance ministers on Monday gave Greece a two-month extension.

Charles Robertson, chief economist at Renaissance Capital, told the Financial Times: "Greece in the next 6 weeks may prove to be more important for global markets than Russia/Ukraine was in 2014.

"A possible Syriza election victory may force the eurozone to choose between a fiscal union (debt write off for Greece) or the first Euro exit."

Markets also fell off a cliff in China for separate reasons. China's financial markets tumbled 5.4% as the government tightened lending regulations and proclaimed the virtues of slow economic growth.

Wall Street also declined on Tuesday, but less dramatically than in Greece and China.

Contributing: Associated Press