The political parties who are to form Israel's next government are likely to sign a coalition agreement on Thursday evening, the head of the new centrist Yesh Atid party said.

"It's apparently the end. Or actually the start," Yesh Atid leader Yair Lapid wrote on his Facebook page, saying the signing of the deal was "likely to be tonight."

"Barring any last minute hitches, it should be signed today," said Ashley Perry, spokesman for the hardline Yisrael Beitenu which ran on a joint electoral list with Prime Minister Benjamin Netanyahu's rightwing Likud.

"Early next week will be the swearing-in of the new government," he added.

A Monday ceremony would be just two days before a key visit by US President Barack Obama.

"There is a government," Likud spokeswoman Noga Katz told AFP, saying details of the line-up would be released "in due course."

News reports said the agreement would see Netanyahu heading a coalition commanding 68 seats in 120-seat Knesset, comprising Likud-Beitenu (31), Yesh Atid (19), Naftali Bennett's far-right Jewish Home party (12) and the centrist HaTnuah (6) headed by former foreign minister Tzipi Livni.