Russian state arms producer Almaz-Antey said on Tuesday it would supply Iran with the advanced S-300 missile system once a commercial agreement is reached.
The company's chief executive, Yan Novikov, confirmed Moscow had removed restrictions on deliveries to Tehran that were imposed under pressure from the West in 2010.
He did not say when the deliveries might go ahead or how close a deal was.
"All restrictions have been lifted by the political authorities. When there is a contract, we will supply the system, including to Iran," he told a news conference when asked whether Almaz-Antey would supply the missile system to Iran.
President Vladimir Putin signed a decree in April ending the self-imposed ban on selling the S-300 system to Iran. His decision came after world powers, including Russia, reached an interim deal with Iran on curbing its nuclear program.
Russia hopes to reap economic and trade benefits if a final deal is concluded to build on the framework agreement reached in the Swiss city of Lausanne between Iran and six world powers — Russia, the United States, France, Britain, Germany and China.