Plane manufacturer Boeing has received a license to export spare parts for commercial aircraft to Iran, according to the BBC.
Boeing has had no public dealings with Tehran since 1979.
The license is seen as part of a temporary agreement to ease sanctions on Tehran following the nuclear framework agreement between Iran and six global powers reached last November.
Boeing said in a statement that the license had been granted out of concern for the safety of flight.
On Friday, General Electric announced it had received United States permission to overhaul 18 engines sold to Iran in the late 1970s. The work will be carried out at GE facilities or at German firm MTU Aero Engines, it said.
Iran Air is still flying passenger planes bought before the 1979 hostage crisis, during which 52 Americans were held hostage in Tehran for 444 days.
Iran has reportedly argued that sanctions imposed after the hostage ordeal have prevented Tehran from upgrading its plane fleet and reduced the safety of its aircraft.
There have been more than 200 accidents involving Iranian planes in the past 25 years, leading to more than 2,000 deaths, according to media reports.
Boeing said the license covers only components required to ensure ongoing safe flight operations of planes it sold before Iran's revolution in 1979.
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