BBC News
Dr Karim Pouladian-Kari, 45, from Guildford in Surrey, was convicted of knowingly attempting to export the electrical switchgear parts in 2009.
The Old Bailey had heard he was denied a licence because of the risk the parts could be used to make weapons.
Dr Pouladian-Kari had denied the parts could be used for military purposes. He will be sentenced on 12 December.
The court heard Dr Pouladian-Kari ran a company called GTC Associates, based in Guildford, which exported parts to Iran Tablo Co (ITC) on 2 September 2009.
Shipment stopped
The goods were passed for export at the Port of Dover in Kent because computer systems were down for maintenance on that day.
Dr Pouladian-Kari was later told a licence had been denied, even though the shipment had already left the country.
The jury heard he then attempted to export another shipment to ITC, which was stopped at Dover on 24 November 2009.
Dr Pouladian-Kari had said the parts would be used to protect human life against electrical faults such as short circuits.
He had denied one count of being knowingly concerned in the attempted exportation of goods subject to a prohibition or restriction.
He will be sentenced along with his employee Arbrene Hussain, 32, from Guildford, who admitted the same charge at an earlier hearing.
