The European Union instituted sweeping and legally binding sanctions against Iran Monday amid ongoing concerns about Tehran's nuclear ambitions and brinkmanship – and continued reprocessing of nuclear fuel. European foreign ministers in Brussels finalized measures that will take effect tomorrow, targeting a wide range of banks, individuals, shipping, insurance, and oil refining technology – despite financial losses to European firms that have greater investment and dealings with Iran than their US counterparts. These Iran sanctions go farther than a fourth round of United Nations sanctions approved June 9 and are seen as the most comprehensive the EU has ever undertaken against a single state.The precise sanctions list will be published tomorrow. But Iran’s energy sector is known to be a main target of the sanctions. Oil accounts for roughly 80 percent of total exports and more than half of the government's revenues. Despite being the No. 2 OPEC exporter of crude oil, however, Iran must import some 40 percent of its refined gasoline – making it vulnerable to European limits on such imports. Tehran announced on Sunday a $46 billion program to increase its oil refining capacity, adding seven new refineries and improving its nine existing ones.