The development shows Iran breaking through yet another barrier in its bid to regain oil market share lost during years of international sanctions that hindered its sale of crude oil and condensates to the international market.
The supertankers Snow and Huge, which are owned by National Iranian Tanker Co. (NITC), the country's oil shipping operator, loaded crude oil at Iran's Kharg Island and are en route to
Rotterdam in northwest Europe, tracking data showed. Each of the tankers is carrying 2 million barrels of oil.
Iran has steadily reconnected with buyers across Europe since sanctions were lifted a year ago, but thus far buyers in most of Europe had chartered tankers from other companies.
NITC's own operations were hampered due to their difficulty in securing international insurance cover for their fleet and getting certification, a key requirement for access to many ports around the world, which tests the sea worthiness of ships.
The vessels' success in finding buyers in Rotterdam underscored a potentially easier route into Europe for Iran at a time when the country is likely to target sour crude buyers in Europe more extensively due to cuts from other producers in the Organization for the Petroleum Exporting Countries, notably rival Saudi Arabia.
"It's one less barrier," said Andrew Wilson, head of energy research at BRS Brokers. "If they're going to be able to take some of that market share, it's going to make Rotterdam that much more attractive."
It could also speed the nation's sales from storage aboard its own vessels. Sources told Reuters in early January that the amount of oil Iran held in floating storage on its tankers had dropped by almost half over the previous three month period as Tehran ramped up exports.
One tanker tracking source said the number of tankers storing Iranian oil had fallen to 11 this week from up to 14 at the start of the year, freeing up more of its fleet for trade.
Last week, NITC managing director Sirus Kianersi said the first Iranian crude tanker, leased to "a major Spanish oil company," berthed at the port of Algeciras in Spain "after resolution of insurance, classing, flagging and international certification issues for Iranian vessels."