ATHENS, Greece — Left-wing leader Alexis Tsipras threw in the towel Wednesday on efforts to form a government in politically fractured Greece, deepening the feeling of instability here and making another snap election more likely.

Tsipras’ radical Syriza party was the surprise second-place finisher in Sunday’s general election after a campaign in which he vowed to roll back punishing austerity cuts and tear up Greece’s bailout agreements with its international lenders.

But after two days of talks with other political leaders, the brash and energetic Tsipras was unable to stitch together a working coalition in Greece’s highly fragmented new Parliament.

“There was sweeping social support but weak political backing. Our dream of a leftist coalition cannot materialize,” he said after meetings with the head of the top vote-getting conservative New Democracy party and the third-place Socialists.

On Thursday, the task of trying to put together a government will fall to Socialist leader Evangelos Venizelos, the former finance minister. But few expect him to succeed where first New Democracy leader Antonis Samaras and then Tsipras failed.

President Karolos Papoulias would then try to bring the leaders together to form a government of national unity. But many analysts expect that, in the end, Papoulias will announce a new election to take place as early as June 17. Whether it would produce a decisive result is anyone’s guess.

The volatility comes as Greece is on the hook to approve yet another round of deep public spending cuts as a condition of receiving its next installment of bailout loans. Without the money, Greece faces the prospect of a chaotic default, which would have worrisome repercussions for the global economy.

Tsipras already had sent shock waves through the markets with his declaration Tuesday that he intended to renege on the bailout agreements.