Millions of Iranians voted to choose a new president on Friday (June 14), urged by Supreme Leader Ayatollah Ali Khamenei to turn out in force to discredit suggestions by arch foe the United States that the election would be a sham.

The 50 million eligible voters had a choice between six candidates to replace incumbent Mahmoud Ahmadinejad, but none is seen as challenging the Islamic Republic's 34-year-old system of clerical rule.

Widely referred to as an 'epic' vote by state media, candidates came out in force on Friday to say they would support the victor.

The first presidential poll since a disputed 2009 contest which led to months of unrest is unlikely to change rocky ties between the West and the OPEC nation of 75 million, but it may bring a softening of the antagonistic style favoured by Ahmadinejad.

World powers in talks with Iran over its nuclear programme are looking for any signs of a recalibration of its negotiating stance after eight years of intransigence under Ahmadinejad.

Voting in the capital Tehran, Iran's Supreme Leader Ayatollah Ali Khamenei called on Iranians to vote in large numbers and derided Western misgivings about the credibility of the vote.

On May 24, U.S. Secretary of State John Kerry questioned the credibility of the election, criticising the disqualification of candidates and accusing Tehran of disrupting Internet access.

All the remaining contenders except current chief nuclear negotiator Jalili have criticised the conduct of diplomacy that has left Iran increasingly isolated and under painful economic sanctions.

The Interior Ministry announced that voting, initially due to end at 1330 GMT, would be extended by several hours, Iran's Press TV reported in mid-afternoon.

In the past, authorities have cited such extensions as evidence of a high turnout.

With no reliable opinion polls in Iran, it is hard to gauge the public mood, let alone the extent to which Khamenei and the Revolutionary Guards exert their influence over the ballot.

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