Moscow is already at odds with the West over its nuclear ties with Tehran but has sought to use its warm relations with Iran to be recognised as a key mediator between the West and the Islamic Republic.
The Vedomosti business daily cited military sources as saying Iran would buy 29 TOR-M1 systems designed to bring down aircraft and guided missiles at low altitudes.
The paper, calling it the biggest sale of Russian defence hardware to Iran for about five years, said Moscow and Tehran had already signed the contract.
Interfax news agency separately quoted a source as saying the deal, which would also include modernising Iran’s air force and supplying some patrol boats, was worth more than $1 billion.
The move, likely to irritate Israel and the United States, could strain Moscow’s efforts to broker a deal between Iran and European negotiators aimed at breaking a deadlock over Tehran’s nuclear programme.
Israel in particular is nervous about Iran’s military potential after President Mahmoud Ahmadinejad said in October that Israel should be “wiped off the map” — comments condemned by Russia at the time.
Russia’s Defence Ministry declined to comment on the deal. Officials at state arms exporter Rosoboronexport, Russia’s state defence supplier, were not available for comment.
Western countries suspect Iran of seeking nuclear weapons under the cover of a civilian atomic programme, which Tehran denies, saying it wants only to generate electricity.
Russia has helped Iran build its first nuclear reactor and is preparing to launch it next year. Some in the West fear that Iran could use Russian know-how to make sensitive weapons.
The defence industry source told Interfax there were no international restrictions on selling weapons to Iran.
“Moreover, practically all the weapons that Russia is delivering to Iran in the coming years are defensive rather than offensive in character,” the source said.
One Western diplomat who closely watches Russia-Iran dealings said news of the deal was alarming and would further increase tensions.
“Russia has long positioned itself as a major peace broker between Iran and the West — and all of a sudden they are throwing this bombshell. It just does not make any sense,” said the diplomat, who asked to remain anonymous.
(Additional reporting by Maria Golovnina)
