FACTBOX: Sanctions against Iran

(Reuters) - Iran said on Sunday Western countries would be the ones to suffer if they passed a new U.N. sanctions resolution on the Islamic Republic.

Iran has failed to convince world powers that its nuclear program has only peaceful aims. Britain and France have said they hope the United Nations Security Council will vote next week on a third round of sanctions.

Following are details about what more sanctions could involve and those already imposed by the U.N. Security Council and the United States.

* WHAT COULD MORE U.N. SANCTIONS INCLUDE?

-- Last week France and Britain formally submitted a third sanctions resolution against Iran to the U.N. Security Council.

-- The resolution calls among other things for asset freezes and mandatory travel bans for specific Iranian officials.

-- It also expands the list of Iranian officials and companies targeted by the sanctions and repeats the council's demand that Iran halt its uranium enrichment program.

-- Russia and China, both commercial partners of Iran, have hardened their opposition to new sanctions since a U.S. report recently said Iran halted its nuclear weapons program in 2003.

* WHAT SANCTIONS HAVE BEEN IMPOSED?

UN SANCTIONS:

-- The U.N. Security Council has imposed two sets of sanctions on Iran, in December 2006 and March 2007. Both sets were approved by the five permanent Council members -- the United States, France, Britain, China and Russia -- plus Germany, in the so-called P5+1.

-- THE FIRST ROUND: The sanctions covered sensitive nuclear materials and froze the assets of Iranian individuals and companies associated with the program. It gave Iran 60 days to suspend uranium enrichment, a process which can be used to make nuclear power plant fuel or bomb material. Iran did not stop.

-- THE SECOND ROUND: This round included new arms and financial sanctions. It extended an asset freeze to 28 additional groups, companies and individuals engaged in or supporting sensitive nuclear activities or development of ballistic missiles.

-- State-run Bank Sepah and commanders and firms controlled by Iran's Revolutionary Guards, including commanders of one of its units, the Qods Force, were included on the list.

-- The resolution invoked Chapter 7, Article 41 of the U.N. Charter, which makes most of its provisions mandatory but excludes military action. Iran again failed to meet a 60-day deadline to halt enrichment.

* U.S. SANCTIONS:

-- The United States has imposed various sanctions on Iran since 1979 after radical Iranian students stormed the U.S. embassy in Tehran and took U.S. diplomats hostage.

-- The measures prohibit most trade between the United States and the Islamic Republic.

-- In 1995, then President Bill Clinton issued executive orders preventing U.S. companies investing in Iranian oil and gas and trading with Iran. However Tehran has found plenty of other willing customers outside of the United States.

-- The same year, U.S. Congress passed the Iran-Libya Sanctions Act (ILSA) -- from which Libya was later dropped -- requiring the U.S. government to impose sanctions on foreign firms investing more than $20 million a year in Iran's energy sector. It was extended for five years in September 2006. No foreign firms have been penalized.

-- Iran is the world's fourth biggest exporter of crude and has capitalized on China and India's growing demand for oil, boosting its crude exports to Asia to 70 percent of its total crude exports of roughly 2.5 million barrels per day.

-- In October 2007 the U.S. slapped sanctions on Bank Melli, Bank Mellat and Bank Saderat and also branded the Revolutionary Guards a proliferator of weapons of mass destruction. Washington also imposed sanctions on firms controlled by the Guards and on the Qods Force, saying the unit backed terrorists.

-- The United States recently slapped sanctions on Brig-Gen. Ahmed Foruzandeh from the Qods force for fomenting violence in Iraq.

(Writing by David Cutler and Edmund Blair; London Editorial Reference Unit;)