Russia says it has offered to supply Iran with Antey-2500 antiaircraft missile systems instead of S-300s, which have been the subject of a dispute between the countries for five years.
The head of state-owned Russian conglomerate Rostec, Sergei Chemezov, told reporters on February 23 that Iran is "considering the offer" and had not yet made a decision.
Russia agreed in 2007 to deliver five high-precision S-300 systems to Iran, causing concern in Israel and the United States.
In 2010, President Dmitry Medvedev canceled the contract after Russia joined other UN Security Council members in approving sanctions designed to stop the sale of arms to Iran over its nuclear program.
Iran sued in an international court, seeking to force Russia to honor the contract or pay compensation.