Athens:
Greece's prime minister says he will reshuffle his Cabinet on Thursday and seek a vote of confidence for his new government in Parliament, after coalition talks with Opposition parties failed.
The discussions came as anti-austerity riots hit Central Athens.
Prime Minister George Papandreou has struggled against falling approval ratings and an internal party revolt among the governing Socialists over a new package of austerity measures.
The measures must be passed by Parliament before the end of the month if debt-ridden Greece can continue receiving funding from its international bailout.
Hundreds of protesters clashed with riot police in central Athens earlier on Wednesday as the the main square was blanketed outside Parliament with tear gas during a previously peaceful rally by more than 25,000 people.
The country needs political unity on a new austerity package to avoid a devastating default which would undermine the future of the eurozone.
Wednesday's chaos triggered a sell-off in global financial markets as investors worried about a chain reaction that experts predicted would be catastrophic.
Under such pressure, Papandreou and conservative party leader Antonis Samaras discussed the creation of a power-sharing government to deal with the country's crippling debt crisis during a telephone conversation, an Opposition party official said.
The official said the conservatives' conditions for participating in a potential grand coalition were that Papandreou leaves his current position as prime minister, and the new government re-negotiate the bailout agreement.
Wednesday's riots broke out and lasted several hours after large crowds gathered outside Parliament and as unions held a general strike to protest against the new austerity measures.
At least 11 people were injured and another 20 people were detained, according to police, as protesters responded to tear gas by hurling stones and firebombs.
Cafe tables and chairs lay overturned as trash bins burned. Heavy clouds of tear gas hung over Syntagma Square and side streets.
Police set up a massive security operation to ensure protesters could not carry out a pledge to prevent lawmakers from accessing Parliament.
Papandreou has suffered plummeting approval ratings and an open revolt from within his own PASOK Socialist party over the new austerity bill, which is set to increase taxes and cut spending until 2015 - two years beyond the current government's mandate.
But the new austerity package, worth 28 billion euros (40.5 billion US dollars), must be passed if Greece is to avoid bankruptcy.
The country has been dependent for the past year on a 110 billion euro package of bailout loans from other European Union countries and the International Monetary Fund to prevent it from defaulting on its debts.