Ukrainians voted for a new president yesterday and an exit poll issued after polls closed said a West-leaning liberal had beaten the ex-Soviet state's Russian-backed prime minister.

The run-off vote was the culmination of a bruising campaign. Many fear the aftermath of the election could produce turmoil if the result proves close and contested.

The exit poll, conducted by Ukrainian research organisations, gave opposition leader Viktor Yushchenko 54 per cent of the vote against 42 per cent for Prime Minister Viktor Yanukovich, the establishment candidate.

Mr Yushchenko, an economist who favours gradual integration with the West, had topped the first round last month by less than one percentage point.

He had warned that officials would cheat to boost the chances of Mr Yanukovich, backed by both the Ukrainian establishment and Russia. But he predicted he would win anyway.

The exit poll was conducted by the Kiev International Institute for Sociology and the Razumkov Centre, which said they had tried to increase accuracy by not requiring those polled to give their names in public.

Two Ukrainian exit polls after the first round had varying degrees of accuracy.

Pollsters acknowledged that their effectiveness was reduced by fear among those being questioned.

There was no indication how long the official count would take. Ten days were needed in the first round.