Chris Morris: MHP's performance surprised everyone

Mr Ecevit is expected to be reappointed prime minister after his party, the Democratic Left, topped the poll.

With most of the votes counted, his party had just over 22% of the vote, according to Turkish TV.

However, he faces a resurgent right wing as he contemplates putting a coalition together.

The Nationalist Action Party, the MHP, won an estimated 18% of the vote, after failing to take a single seat in the previous election.

Mr Ecevit has formally resigned and will serve as caretaker prime minister until the results are finalised.

The figures mean the new government will have to be a coalition, and will need the support of at least three parties in the new parliament. The MHP is likely to demand several important ministerial posts.

The MHP's success was at the expense of the pro-Islamist Virtue Party, which suffered a major loss of support.

In local elections in the south of the country, the pro-Kurdish party, Hadep, also did well, gaining a huge majority in the eastern city of Diyabakir.

BBC Ankara Correspondent Chris Morris says its success appears to mark a further polarisation of opinion on the Kurdish issue.

Caution on coalition plans

Mr Ecevit, a political veteran who first became prime minister 25 years ago, claimed victory at a late night news conference.

Pro-Kurdish Hadep did well in the southeast

But he refused to be drawn on which other parties he planned to bring into his government.

"The results show the DSP will be the first party in these elections. But before results are officially declared ... I don't think it right to enter into coalition calculations," he said.

MHP leader Devlet Bahceli, a 51-year-old economist, was quoted in the Turkish media as saying he would be prepared to enter into a coalition with the DSP and Mesut Yilmaz's conservative Motherland Party.

"We will not insist on our own programme being implemented. We will strive to find a middle road but we will not make too many concessions," he said to the Sabah newspaper.

The DSP and MHP have a history of conflict dating back to the 1970s, when supporters of left and right fought bloody street battles that led eventually to a 1980 military coup.