Leaders of the three largest parties after Tuesday's election began meeting with their rivals and other party heads yesterday in a bid to build a coalition.

Yesterday morning, MK Yoel Hasson (Kadima) said a team would begin immediate negotiations to forge a coalition led by Kadima chairwoman Tzipi Livni.

Livni told Yisrael Beiteinu's Avigdor Lieberman that she was the people's choice for prime minister, and they agreed to hold further talks. Speaking before the meeting, Livni vowed to fight to become the next prime minister.

"The people chose me in droves. I feel a great responsibility to translate the power vested in me into action, to advance the country and to unify the people," said Livni from her Tel Aviv home.

Earlier in the day, Lieberman said he was leaving his options open. He and Likud chairman Benjamin Netanyahu met in Jerusalem later to discuss a Netanyahu-led coalition.

Lieberman, whose party won 15 Knesset seats, is seen as the pivotal coalition partner. Without Yisrael Beiteinu, neither Kadima nor Likud could form a stable coalition.

Netanyahu, meanwhile, met earlier in the day with Shas leader Eli Yishai, whose party received 11 Knesset seats.

"We committed ourselves before the election to recommend the president choose Benjamin Netanyahu to form the government," Yishai told Army Radio yesterday morning. "The people's choice is a rightist government. This, of course, doesn't rule anything out."

Sources in Yisrael Beiteinu said yesterday they would not rule out joining a coalition that included Shas, despite Lieberman's pledge Tuesday that he would not forget Shas' attacks on his party and himself. Shas spiritual leader Rabbi Ovadia Yosef had said Saturday, "Whoever votes for Lieberman gives strength to Satan."

"We aren't making an ultimatum," said a senior Yisrael Beiteinu official. "It also doesn't matter for us that Bibi's first meeting is with Shas. Everything depends on the fundamentals."

Shas and United Torah Judaism are trying to put together an ultra-Orthodox bloc to negotiate with Netanyahu in an effort to knock Yisrael Beiteinu down a peg. The bloc would have 16 Knesset seats, compared to the 15 Lieberman brings to the table.

The chairman of Habayit Hayehudi, Daniel Hershkowitz, is scheduled to meet this afternoon with Netanyahu at Likud headquarters in Tel Aviv.