Up to 109 million registered voters were taking part in the election in the world's biggest country, including reindeer herders in the far north east near Alaska, ice swimmers in Siberia and troops at military bases in Moscow.

Exit polls and first official results were due after polls close in Russia's 11th and final time zone, the European enclave of Kaliningrad near Poland at 8pm local time on Sunday.

The Kremlin's candidate and the almost certain victor, 42-year-old First Deputy Prime Minister Dmitry Medvedev, cast his ballot in the Moscow sleet on Sunday morning with his wife Svetlana, telling reporters: 'I feel good. Spring has come.'

A smiling Mr Putin voted in Moscow at the Academy of Sciences with his life Lyudmila but did not speak to reporters.

Opposition politicians denounced the election on the eve of the poll as a 'farce', saying biased media coverage and harassment of challengers made the contest completely one-sided.

But polls suggest most voters want to reward Putin for eight years of rapid growth and rising wages by backing his chosen successor. Record prices for Russia's main exports of oil, gas and metals have fuelled the biggest boom in a generation.

Surveys predict that Mr Medvedev, who trained as a lawyer and first worked with Putin in the St Petersburg town hall 18 years ago before following him to the Kremlin, will win about 70 per cent of the vote.

'I voted for Medvedev. I think he's young and clever and will work well in tandem with Putin,' said a 70-year-old Moscow resident who gave his name as Georgy when he cast his ballot.

Mr Putin, by far Russia's most popular politician, has said he will become prime minister under Mr Medvedev - an unusual division of power in a country accustomed to an all-powerful supreme leader.

It remains unclear how the new arrangement will work once Mr Medvedev is installed in the Kremlin and his former boss and mentor moves to the prime minister's quarters further along the river to start a role which, on paper, is much more lowly.

Some voters expressed disenchantment with what they said was a phoney campaign, during which Mr Medvedev barely appeared on the hustings at all, avoided giving interviews and shunned debates with his challengers.

Andrei, a 22-year-old student who declined to give his full name, said: 'I voted for Medvedev because I think he's the best candidate but I wish there were more serious candidates'.

Mr Medvedev's principal opponents are 63-year-old Communist veteran Gennady Zyuganov, who first ran for president 12 years ago, and 61-year-old nationalist firebrand Vladimir Zhirinovksy.

Neither is predicted to win more than 15 per cent.

Liberal independent candidates were either barred from running for alleged violations of election rules or decided to boycott the campaign altogether.

Vyacheslav Karpov, who runs a small advertising business in the Urals city of Yekaterinburg, said he did not need to vote.

'This appointment has taken place without my say-so,' he told Reuters. 'I trust in those who have made the decision for me. Everything has happened perfectly well without me.'

The head of the Central Election Commission, Mr Vladimir Churov, conceded last week that media coverage of the candidates had been 'fair but not equal', arguing that Medvedev deserved more airtime because of his role as First Deputy Prime Minister.

Pollsters predicted turnout would be about 70 per cent, though Kremlin critics said it would be inflated by factory managers and state officials who pressure employees to vote.

Most Western monitors were boycotting the election because of a dispute with Russian election officials over the number of observers allowed and the duration of their stay.

Andreas Gross, head of the only Western observer mission from the Council of Europe, said he would talk on Monday about his findings. Around 300 observers are registered to monitor the election. Most are from ex-Soviet republics friendly to Moscow. -- REUTERS