The meeting of Greek political parties to form a new government would be extend to Thursday, as the negotiations ended without the official resignation of outgoing Prime Minister George Papandreou on Wednesday.

"Political leaders will meet under the president (Carolos Papoulias) at 0800 GMT on Thursday," the president's office said.

It was not clear whether other parties' leaders would attend the political talk that has been held for three days. Left parties leaders refused to take part in Wednesday's meeting.

Earlier on Wednesday afternoon, Papandreou in a televised address to the nation described his selection for the post of new Prime Minister as an "institutional figure," which prompted local analysts to strongly suggest that he was referring to Speaker of Parliament Philippos Petsalnikos.

Greek political crisis has been deteriorating since October 31, when Papandreou announced his plan to call a referendum on the October 26 euro zone summit agreement which he later cancelled under heavy pressure from Greece's European partners who feared that a negative result could destabilize euro zone economies.