Tel Aviv - All but final official results Wednesday morning showed no clear winner in Israel's national elections, promising tough and complicated coalition negotiations ahead.

With all regular ballot boxes - or 99 per cent of the votes - counted, the ruling Kadima party of centrist Tzipi Livni and the opposition Likud party of her hardline rival Benjamin Netanyahu were just one mandate apart.

The remaining one per cent of the ballots, those of Israeli soldiers, sailors and diplomats abroad, are due to be counted Thursday. They could further narrow the gap.

According to the near-final officials results, Kadima remains the largest party in the 120-seat Knesset with 28 seats, but the Likud more than doubled its mandates to 27.

The ultra-nationalist Israel Beiteinu of Moldovan-born immigrant Avigdor Lieberman rose to 15 mandates in Tuesday's elections, making him key to any new coalition.

The Labour Party of Defence Minister Ehud Barak dropped to fourth place with 13 mandates, its worst showing in Israeli history. Party Secretary Eitan Cabel told Israel Radio Wednesday his party should rebuild itself in the opposition.

The ultra-Orthodox Shas party remained a desirable coalition partner as well with 11 mandates, while another religious party - United Torah Judaism, received five.

The pro-settler National Union, the mixed Jewish-Arab Hadash and the United Arab List faction each obtained four, while the religious- nationalist Jewish Home, the Arab Balad faction and the left-liberal Meretz each obtained three seats.

Twenty-five lists did not make it past the threshold of two per cent.

The close call, which was predicted by exit polls on Israel's three news channels late Tuesday, prompted both Livni and Netanyahu to declare victory.

Senior Kadima officials said Wednesday their party's celebrations overnight came "too early" and said it and the Likud would need to form a unity government with a rotating premiership.

A senior Likud legislator, Silvan Shalom, rejected the rotation offer and said it was "clear" Netanyahu should be the next premier. However, he added it was possible to find "common ground" for a unity government headed by the hawkish former premier.

Shas already declared it would support Netanyahu as the next premier. Netanyahu was scheduled to meet Shas leader Eli Yishai Wednesday afternoon to coordinate their positions, while Lieberman was also slated to convene his bolstered faction to debate which candidate to recommend as the next premier to President Shimon Peres.

According to the official results published by the Central Election Commission Wednesday, some 3.2 million of the around 5 million eligible Israelis voted, or 65.2 per cent.

Of those, Kadima received more than 715,000 votes (22.5 per cent), against some 680,000 for the Likud (21.4 per cent).

Lieberman received 11.6 per cent of the vote, against 9.9 per cent for Labour.

Interior Minister Meir Sheetrit, of Kadima, rejected a rotation agreement - as in 1984 between Shimon Peres and Yitzhak Shamir after a similar election outcome - as not practicable. Speaking on Israel Radio, he insisted any new government should be led by Livni. (dpa)