Iran initially denied shooting down the Ukrainian International Airlines plane, this month.
176 people were killed.
However, it admitted a week ago that its military had mistakenly downed the aircraft.
Tehran was forced to make an admission after foreign intelligence on the crash surfaced.
The incident has sparked a wave of anti-government protests in Iran and appeared to expose a rift within the country's leadership.
Now, CNN reports Iran has agreed to transfer the plane's black box to Ukraine.