Greece's Prime Minister Alexis Tsipras is set to call a snap election for 20 September, according to Greek media.
Mr Tsipras has faced a rebellion within his ruling hard-left Syriza party over a new bailout deal which has been agreed with international creditors.
Greece received the first €13bn ($14.5bn) tranche on Thursday, allowing it to repay a debt to the European Central Bank and avoid a messy default.
But the austerity measures needed for the deal angered many in his party.
Mr Tsipras had to agree to further painful state sector cuts, including far-reaching pension reforms, in exchange for the bailout - and keeping Greece in the eurozone.
The overall bailout package is worth about €86bn over three years. The payment of the first tranche was made on Thursday after the bailout deal - Greece's third in five years - was approved by relevant European parliaments.
Mr Tsipras is to make a televised state address later on Thursday.
He is set to submit his resignation to the president to clear the way for the elections, the media reports said.
Energy and Environment Minister Panos Skourletis said on state TV: "The certainty is that the need for elections has arisen."
It was a done deal and apparent ever since that Tsipras convinced enough in the Greek parliament to vote for the bailout package that he would in exchange fall on his sword, and tonight he does just that. The alternative was a vote of no confidence that he clearly would have lost, and so after 8 months the tale of the man elected to stand up to the Troika ends with his complete defeat.
We'll see where Greece goes from here, but the idea that things will be better after a month from now is silly.