TV exit polls showed the hard-liners with about 61 seats in the 120-seat Knesset, Israel's parliament, a bare majority, and the counts could change as actual ballots are tallied.

The unofficial TV results had Netanyahu winning only 31 seats, although he combined his Likud Party with the far-right Yisrael Beitenu for the voting. Running separately four years ago, the two won 42 seats. He expected to increase that total by running together, but the combined list's poll results dipped steadily throughout the three-month campaign.

Netanyahu was also expected to receive stronger backing because his fragmented opposition did not post an agreed candidate against him.

If they hold up through the actual vote counting, the unexpected results could be seen a setback for Netanyahu's tough policies. The coalition-building process could force him to promise concessions to restart long-stalled peace talks with the Palestinians.

Addressing cheering supporters early Wednesday, Netanyahu pledged to work for a broad-based government. Also he said, he would show "responsibility in striving for a genuine peace."

Netanyahu made a quick phone call to a newcomer on Israel's political stage, Yair Lapid, whose centrist party debuted with a strong showing of 19 seats, making it the second-largest party after Netanyahu's.

Nearly 67 percent of Israel's 5.5 million eligible voters took part, more than in previous elections -- apparently giving boosts to the centrists, especially Lapid's new "Yesh Atid" or "There is a future" party, which nearly doubled results predicted by polls before the election.

Lapid's surprise showing could make him a key Cabinet minister should he decide to join Netanyahu's government.

A Likud official said Netanyahu phoned Lapid after the results and told him, "We have the opportunity to do great things together."

Lapid and other centrist parties have said they would not join Netanyahu's team unless the prime minister promises to make a serious push for peace with the Palestinians. The moderates also want an end to the generous subsidies and military draft exemptions given to ultra-Orthodox Jewish communities.

"We have red lines. We won't cross those red lines, even if it will force us to sit in the opposition," said Yaakov Peri, a former security chief and one of Yesh Atid's leaders, told Channel 2 TV.

The conflicting positions of the various parties point up the difficulties facing anyone who tries to set up a coalition government in Israel. If Netanyahu relies only on the religious and hard-line parties, it means constant fights with the opposition over social programs. If he tries to team up with the centrists, it means battles with the ultra-Orthodox over subsidies, as well as internal sniping over concessions to the Palestinians.

Some predicted Netanyahu might even fail to form a government.

"Netanyahu's victory is a pyrrhic victory, and it is not clear he will be the next prime minister," said Israeli political analyst Yaron Ezrahi. "Netanyahu will face difficulty in constructing a viable coalition," Ezrahi said, estimating the life span of the next Israeli government at no more than 18 months.

Netanyahu has won praise at home for drawing the world's attention to Iran's suspect nuclear program and for keeping the economy on solid ground at a time of global turmoil.

Internationally, though, he repeatedly has clashed with allies over his handling of the peace process. Peace talks with the Palestinians have remained stalled throughout his term, in large part because of his continued construction of Jewish settlements in the West Bank and East Jerusalem.

Netanyahu himself has only grudgingly voiced conditional support for a Palestinian state, and his own party is now dominated by hard-liners who oppose that. A likely coalition partner, Naftali Bennett of the Jewish Home Party, which won 12 seats, has called for annexing large parts of the West Bank, the core of any future Palestinian state.

Palestinians viewed the election results grimly, seeing it as entrenching a pro-settlement government.

"Even if Netanyahu brings some center-left parties to his coalition, he will continue building in the settlements," said Mohammed Shtayeh, an aide to the Western-backed Palestinian President Mahmoud Abbas. "He said that clearly, and that is what we expect him to do."

In all, 32 parties ran in the election, and 11 won enough votes to enter the Knesset, according to the exit polls. Israelis vote by putting a slip with a party's initials into an envelope and dropping the envelope into a ballot box, so the process of counting all the votes by hand takes many hours.

Three hours after the polling stations closed, the official Election Commission had published results of only 15 percent out of about 3.5 million votes cast, and the breakdown was similar to the exit polls.

In a sign of the times, many Israelis advertised their voting choice by photographing their ballot slips and uploading them to Facebook.