According to the Islamic Republic of Iran Shipping Lines (IRISL) website, an increase in the volume of imports to Iran in the early 1960s, and the need to regularly transport goods by sea, necessitated the establishment of the first integrated national shipping lines. In August 1967, the first Iranian national shipping company was established, known as Aria Shipping Lines.
Aria Shipping became operational in 1967 with two small vessels in the Persian Gulf area (with a capacity of 1000 and 1550 tonnes respectively) and four ocean-going vessels, the Aria Sep, Aria Far, Aria Naz and Aria Gaam (with the total capacity of 61,252 tonnes), in service between the Persian Gulf, Europe, Asia and America. By the end of 1978, there were 42 Aria shipping vessels with the total capacity of 525,000 deadweight tonnage (DWT).
After the Islamic Revolution and change in economic and political policy on 5 January 1979, the authority renamed Aria Shipping the Islamic Republic of Iran Shipping Lines (IRISL) and affiliated the company to the Ministry of Commerce.
As of August 2012, the IRISL owns a fleet of 115 ocean-going vessels with more than 3.3 million DWT along with 7000 employees both at sea and ashore. It has a capacity to transport 22 million tonnes of cargo annually. 
The IRISL managing director, Mohammad-Hossein Dajmar, has said that according to the United Nations Conference on Trade and Development (UNCTAD), Iran holds a 1.17 percent share of the total shipping capacity in the world, placing the country in nineteenth position globally. 
Impact of Sanctions 2012
International sanctions imposed on Iran in 2012, aimed at stalling the development of Tehran’s nuclear capability, imposed numerous restraints on Iranian shipping. As of 1 July, the EU banned the insurance of tankers carrying oil from Iran. In response, as of August 2012, the Iranian government pledged to provide full insurance cover for all ships, domestic or foreign, carrying Iranian oil. 
The US Treasury in July 2012 released an advisory notice about the flagging of ships by the IRISL. The Office of Foreign Assets Control (OFAC) 'issued the Advisory to ‘alert the maritime industry that IRISL has recently been operating vessels despite their flags having been revoked.’  Reflagging ships disguises their origins, intended to make it possible for Iran to get insurance and financing for the vessels, and find buyers for its oil without attracting attention from the US and EU. Reported on 12 August 2012, 36 Iranian ships had been reflagged with the Tanzanian flag without the country's knowledge or approval, by a shipping agent based in Dubai. According the Al-Jazeera, the National Iranian Tanker Company (NITC) "changed the names and flags of many of its oil tankers ahead of the EU ban, part of sweeping economic measures aimed at pressuring Tehran to end its nuclear programme." 
Reported by the online publication Arab Times, ship brokers and agents said as of February 2012 Iran had at least 20 million barrels of crude, mostly Iranian Heavy grade, at sea in 10 very-large crude carriers (VLCCs) and up to another 20 million barrels in shorter-term storage. “The Iranians sell most of their oil on a landed basis (all costs of transport have to be included the price of the oil),” said Leo Drollas, chief economist at the Centre for Global Energy Studies in London. “They store their oil offshore or bring it closer to their clients. So the oil is already near their customers,” Drollas said. 
IRISL: Official Website
- "IRISL History" IRISL, Retrieved on 10 August 2012.
- "Iran Settles Debts" Maritime Sun, Retrieved on 10 August 2012.
- "Iran Offers Full Insurance for Tankers" Press TV, 28 July 2012.
- "Important Islamic Republic of Iran Shipping Lines (IRISL) Advisory" US Treasury, 19 July 2012.
- "Tanzania confirms reflagging Iran oil tankers" Al-Jazeera, 12 August 2012.
- "‘Sanctions-Hit’ Iran Sells More Oil As Libyan Exports Dwindle" Arab Times, 26 February 2012.