TEHRAN (Reuters) -- A former Iranian prime minister has said he would contest the presidential election in June, a move that could further split the vote for reformers seeking to oust President Mahmud Ahmadinejad.
Iranian news agencies said Mir Hossein Musavi, who was prime minister during the 1980-88 Iran-Iraq war, officially announced his candidacy in a statement.
He becomes the third reformist politician to say he will run on June 12. Ahmadinejad, a conservative, is also widely expected to stand for a second four-year term as president of the world's fourth-largest oil producer.
Former President Mohammad Khatami, who announced his candidacy last month, is widely expected to be Ahmadinejad's main pro-reform challenger.
But analysts say other reformist candidates could deprive him of much-needed votes. Former parliament speaker and reformer Mehdi Karrubi is also running. Ahmadinejad is so far the only leading conservative to let it be known that he will stand.
The outcome of the election could influence Iran's approach in its row with the West over its nuclear program, even though Supreme Leader Ayatollah Ali Khamenei has the final say on such issues.
Musavi was prime minister after the revolution, holding the post between 1981 and 1989. The post was scrapped after he left office.
Khatami oversaw a thaw in relations with the West during his 1997-2005 stint as president. Ties have deteriorated again under Ahmadinejad, who often rails against Iran's enemies.
Khatami worked for political and social liberalization during his time in office, but the hard-liners in charge of key levers of power blocked many of his reforms.