This week's visit to Athens by the head of the euro zone finance ministers' group will mark the start of Greece's negotiations on changing the conditions of its international bailout accord, the finance ministry said in a statement.

Leftist Greek Prime Minister Alexis Tsipras threw down an open challenge to international creditors on Wednesday by halting privatisation plans agreed under the country's bailout deal, prompting a third day of heavy losses on financial markets.

German Finance Minister Wolfgang Schaeuble said on Monday Greece's leader Alexis Tsipras would have to "find a different way" to solve Greece's problems if he says he does not want money from the euro zone bailout program.

Most Asian share markets firmed on Tuesday and the euro clung to rare gains, relieved that European equities had weathered Greece's election outcome without too much disruption.

European shares fell and borrowing costs for the euro zone's most indebted states rose on Monday as the leftist Syriza party looked set to take on Greece's international lenders after a crushing victory in early elections.

The euro skidded to an 11-year low and stock prices fell on Monday as Greece's Syriza party promised to roll back austerity measures after sweeping to victory in a snap election, putting Athens on a collision course with international lenders.

Greece's leftist Syria party held onto its opinion poll lead on Friday as it campaigns to form the first euro zone government committed to scrapping austerity outright after elections this weekend.

Greek leftwing opposition leader Alexis Tsipras said the European Central Bank (ECB) could not exclude Greece if it decides to move to a full "quantitative easing" program to stimulate the euro zone's faltering economy.

Euro zone politicians are not obliged to rescue Greece as the country is no longer of systemic importance to the single currency bloc, a senior member of German Chancellor Angela Merkel's party was quoted as saying.