The EU targetted both Iran's central bank and Tejarat bank, its third largest, as well as shipping firms and three senior Revolutionary Guards in new sanctions this week, the EU Official Journal said on Tuesday.
In all, the journal named 11 firms targetted by a European Union assets freeze, with the country's central bank listed as trying "to circumvent sanctions" that are already in place.
The journal said the Tejarat bank, which was also targetted by the United States on Monday, moved tens of millions of dollars last year to help the Atomic Energy Organisation of Iran to acquire yellow-cake uranium.
Tejarat bank is said to have around 2,000 branches in Iran and foreign offices in France and Tajikistan.
EU foreign ministers agreed sanctions against the central bank as well as an unprecedented gradual oil embargo on Monday as Western powers rounded on Tehran to return to negotiations amid concerns it is inching ever closer to building a nuclear bomb.
Also listed were five shipping companies, two of them based in the EU -- BIIS Maritime in Malta and Hanseatic Trade Trust & Shipping in Hamburg -- and some of them subsidiaries of the state-sponsored IRISL shipping group.
One, Tidewater Middle East, was listed as being controlled by Iran's Revolutionary Guards.
Other firms were listed as having served as front companies for covert procurement, illicit arms dealing as well as arms transfers to Syria.
The three Iranians designated included Ali Ashraf Nouri, a Guards deputy commander who heads the political bureau.
The EU has already frozen the assets of 433 firms and 113 individuals, as well as restricting trade and investment in the oil and gas industries.
Meanwhile, Australia will follow the EU lead in banning oil imports from Iran, the country's foreign minister Kevin Rudd said on Tuesday.
"On the question of Iran, let me be absolutely clear (regarding) the actions taken in Brussels yesterday on sanctions by the European Union -- we in Australia will undertake precisely the same parallel action for Australia," he told reporters during a visit to London.