The governing centrist Kadima won 28 seats and the right-wing Likud opposition won 27 - both well short of the 61 needed to form a government.

The ultra-nationalist Yisrael Beiteinu came third with 15 seats.

Israel's president is expected to begin consultations next week about which party to ask to form a government.

The election results - if confirmed - push the Labour party led by Defence Minister Ehud Barak into an unprecedented fourth place.

Coalition bids

Speaking at a victory rally, Kadima's Tzipi Livni told supporters she was ready to lead the country.

However, Likud's Benjamin Netanyahu said that with God's help, he would lead the next government.

The country's largest newspaper, Yedioth Ahronoth, ran the headline "Political stalemate" alongside photographs of both leaders.

Analysts say that gains by right-wing parties could give Mr Netanyahu a better chance of forming a coalition.

On the basis of the exit polls, Likud and various nationalist parties control 65 of 120 seats in the Knesset.

Yisrael Beitenu leader Avigdor Lieberman said his party wanted a right-wing government, but added "we do not rule out anyone".

He met with Ms Livni on Wednesday as the ruling Kadima party attempted to forge a coalition.

"This is an opportunity for unity that can promote issues that are important for our two parties. They agreed to continue their contacts," Ms Livni's office was quoted as saying by news agency AFP.

Her rival Mr Netanyahu later met Mr Lieberman, as well as the head of Shas, Eli Yishay, on Wednesday.

It is thought that coalition negotiations could take weeks.

Likud had held a solid lead in opinion polls prior to the election, but Kadima closed the gap in the final days.

However several smaller parties, whose support Ms Livni would need, are opposed to some of her policies, especially her pledge to exchange land for peace with the Palestinians.

Final results are expected within days.

BBC diplomatic correspondent Jonathan Marcus says the closeness of the forecast result is in many ways the worst outcome for Israeli democracy, as it sets the scene for days and probably weeks of fractious political horse-trading.

Once final results are in, President Shimon Peres will consult party leaders to determine who among them stands the best chance of

forminga coalition government, but he does not have to nominate the leader of the largest party.

Whoever is chosen then has up to 42 days to form a coalition. If the attempt fails, Mr Peres can ask another leader to assume the task.

The election has been dominated by security issues following Israel's offensive in the Gaza Strip controlled by the Palestinian militant group Hamas.

Although its rival in the West Bank, the Palestinian Authority, has not expressed preference for any candidate, senior negotiator Saeb Erakat expressed dismay right-wing parties that oppose the traditional land-for-peace formula had performed so well.

"It is obvious the Israelis have voted to paralyse the peace process," he said.

In Kuwait, French president Nicolas Sarkozy said he hoped Israel's new leadership would "have an obsession with peace... which is the guarantee of Israel's security," AFP quoted him saying.

Elections were called early after Ms Livni failed to form a new government following Prime Minister Ehud Olmert's decision to step down last year amid a corruption probe against him.

Mr Olmert will stay on as caretaker prime minister until a new government is formed.