He said that two million barrels has been purchased by French Total Company and the other two million barrels by two Russian and Spanish companies.
Javadi said that the Russian company will ship oil to its refinery in Romania.
Iran had already declared that in post-sanctions era will increase its oil export in two phases one million bpd.
Petroleum Minister Bijan Zangeneh said following his visit to Italy and France that contract to sell 160,000 barrels crude oil to Total will be executed on February 16, 2016.
He called Italian Oil Companies of Eni and Saras as traditional customers of Iranian oil, which will purchase oil in post-sanctions era.
Iran intends to offer discount to retake its European share from rivals.
Before intensification of sanctions, Iran exported 500,000 bpd oil to Europe, which later it reduced to 100,000 bpd.