Former Iranian President Mohammed Khatami has decided to withdraw from the upcoming presidential election to avoid splitting the pro-reform vote, a senior adviser said on Monday. The adviser, who spoke on condition of anonymity, said the reformist politician has made his decision but has not made a public announcement yet. The state-run news agency Fars also reported on Monday that Khatami would not challenge President Mahmoud Ahmadinejad. Instead, Khatami had decided to support another reformist candidate, Mir Hossein Mousavi, according to CNN International. Khatami had yet to make an official announcement as of early Monday evening, but a close ally said on his Web site that Khatami was expected to formally announce his decision later in the day. During the time that Khatami served as president from 1997 to 2005, he faced very harsh opposition that prevented him from implementing any of his liberal and reformist ideas, says Menashe Amir, an Iranian affairs expert and chief editor of the Foreign Ministry's Persian language Web site. According to Amir, Khatami, who announced his candidacy five weeks ago, said from the very beginning that he would withdraw if a better candidate presented himself. Mousavi is considered moderate when it comes to internal economic and social problems, but espouses a more radical Iranian revolutionary ideology, Amir said. "He is as hard as others concerning international issues, like peace with the Palestinians and relations with the US," adding that "there is a hope that Mousavi can be a bridge between so-called reformists and so called extremists, the dogmatists, in Iran." Khatami had received death threats after he announced his intention to run and his candidacy had produced very tense relations between him and Ahmadinejad's supporters. While Mousavi is considered much better to handle the Iranian economic problems and to improve the country's image internationally, Ahmadinejad is supported by the Revolutionary Guards, who are very powerful in Iran and fear that Mousavi will cut their military budget to solve the country's economic problems, Amir said. Mousavi served as prime minister in Iran during the Iran-Iraq war, and successfully steered the country through difficult economic times. Khatami told his supporters during a meeting late Sunday that Iran's ruling clerics may resist his agenda, and that Moussavi will face less resistance. Mousavi announced last week that he would run in the June 12 elections. His candidacy could pose a serious challenge to the incumbent hard-line President Ahmadinejad. "Rest assured that Mousavi will recruit a remarkable percentage of votes from the other side. I have reports that some conservatives will not vote for me and this guy Ahmadinejad, but they would definitely vote for Mousavi," Khatami told his supporters. He said that he and Mousavi share about 20 to 30 percent of the reformist vote.