President Mahmoud Ahmadinejad is seeking a second term in office
Iran's electoral council has approved the four main candidates for the 12 June presidential poll, reports say.
They include President Mahmoud Ahmadinejad, who is seeking a second term in office, the semi-official Mehr news agency said.
Two leading reformists have also had their qualifications approved - former Prime Minister Mir-Hossein Mousavi and ex-parliament speaker Mehdi Karoubi.
Former Revolutionary Guards chief, Mohsen Rezai, can also run.
"The name of candidates... approved by the [Guardian Council] are as announced:
, Karoubi, Mousavi and Mohsen Rezai," said an Iranian Interior Ministry statement quoted by state media.
The 12-member Guardian Council has the power to approve candidates for elections in
In keeping with the constitution, candidates must believe in the principles of the Islamic republic and have a prominent political and religious background.
More than 450 Iranians, including 42 women, had registered as prospective candidates but only the four leading contenders were accepted.
Campaigning is already well underway in Iran, the BBC's Jon Leyne reports from Tehran, with all the candidates seeking to replace Mr Ahmadinejad heavily criticising his management of the economy.
Some have also criticised his comments on the Holocaust and called for a less confrontational foreign policy, our correspondent adds.
Campaigning will run until 10 June, with results due to be declared a day after the 12 June vote.
Some 46 million Iranians are eligible to vote in the poll, which will be Iran's 10th presidential election since the 1979 Islamic revolution.