Greece's main two political parties have agreed on an interim prime minister to take the crisis-hit country out of deadlock and avert a looming bankruptcy, state television NET said.

The new premier will be named tomorrow along with the rest of the cabinet following the conclusions of negotiations between outgoing Prime Minister George Papandreou and main opposition leader Antonis Samaras, it said.

The apparent breakthrough came after a day of tough haggling between the ruling socialist party and the conservatives, with former European Central Bank vice-president Lucas Papademos heavily tipped to be offered the post.

Papademos duly flew to Athens from the United States, but was reported to have set conditions to accept what is currently one of the most thankless jobs in Europe.

One of his requests, according to reports, was an open-ended deadline for early elections to allow debt-wracked Greece to conclude negotiations with the EU on a new bailout deal that was only brokered last month.

Papandreou and Samaras had earlier agreed to hold elections in mid-February.

Adding to the pressure, both the European Commission and the United States urged Athens to finalise its government and swiftly act on fulfilling conditions of the EU bailout.