Iran will hold run-off elections for 65 parliamentary seats, state media said on Monday, after loyalists to the paramount clerical leader won a dominating majority at the expense of President Mahmoud Ahmadinejad.

The widespread defeat of Ahmadinejad's allies in the 290-seat assembly is expected to reduce the president to a lame duck for the rest of his second and final term, and increase Supreme Leader Ayatollah Ali Khamenei's influence in the country's 2013 presidential election.

Khamenei swiftly endorsed Ahmadinejad's re-election in 2009, rejecting opposition allegations of widespread fraud that led to eight months of unrest, crushed bloodily by security forces.

But a rift opened between the two leaders after - critics of Ahmadinejad said - the president tried to undermine the leading political role of clergy in the Islamic Republic.

With all ballot boxes counted, Khamenei acolytes were expected to occupy more than three-quarters of the 290 seats in the Majlis (parliament), according to a list published by the interior ministry on Sunday.

But state television said 130 candidates were going to compete in run-offs next month for 65 seats in 33 constituencies.

In the race for the 30 seats in (the capital) Tehran, five candidates were able to secure seats and 50 candidates will compete for the 25 remaining seats, Interior Minister Mostafa Mohammad Najjar was quoted as saying by state television.

Among the five candidates who secured seats in Tehran, Gholam-Ali Haddad Adel, a key ally of Khamenei and father-in-law to his son Mojtaba, was the most popular.

CONTEST OF CONSERVATIVES

In the absence of pro-reform figures, whose two main leaders are under house arrest, Friday's vote amounted to a contest between conservative hardliners split into pro-Khamenei and pro-Ahmadinejad camps.

Pro-reform politicians, including reformist former president Mohammad Khatami, decided to keep a low profile by not introducing a unified list of candidates, saying their demand for a free and fair election had not been met.

Khatami's decision to cast his vote on Friday was followed by a wave of criticism from leading pro-reform politicians and their supporters.

In a statement on Monday, the former president said that pro-reform groups' decision not to give out a list never meant boycotting the election, adding that he hoped reformists could set themselves free of the past and start a new future.

I have acted from the stance of reforms as I believe reforms are the only way ... to achieve people's rights and the nation's interests and also to counter threats from inside and outside the country, Khatami said in his statement, according to ISNA news agency.

The election outcome will have no significant impact on Iran's foreign policy, which is determined by Khamenei and one of whose salient features is defiance of increasing Western pressure on Tehran to curb its nuclear programme.

Iran denies accusations that it is trying covertly to develop nuclear weapons capability, saying it is enriching uranium only for a future network of nuclear power plants.

Ahmadinejad is likely to be summoned to an unprecedented hearing in the outgoing parliament by Friday to answer questions focusing on his rocky handling of the economy.

Critics say Ahmadinejad has inflicted higher inflation on Iranians by slashing food and fuel subsidies to cut spending and purge waste, and replacing them with cash handouts of around $38 a month per person.

Under mounting pressure over its nuclear activity and aware of the possibility of an Israeli attack, Iran's clerical elite called for a high turnout in the election to repair damage done to its legitimacy by the violent crackdown on the pro-reform movement after Ahmadinejad was re-elected in 2009.

Najjar said the turnout stood at 64 percent, 11 percent higher than in the 2008 parliamentary vote. The result of this vote was a slap in the face and a punch in the mouth of the enemies, he said, according to state television.

(Writing by Zahra Hosseinian; Editing by Tim Pearce)