The U.S. State Department said Edison International pulled out of a contract to explore the Dayyer natural gas field in Iran.
U.S. and European sanctions targeting the Iranian energy sector went into force at the beginning of the month. Victoria Nuland, a spokeswoman for the U.S. State Department, said Edison joins Total, Royal Dutch Shell, Statoil, Japan's INPEX and Italian counterpart Eni in backing away from Iran.
"These companies have recognized the risks of doing business in Iran's energy sector given Iran's proliferation activities, support for terror networks around the world, and other destabilizing actions," she said in a statement.
U.S. Secretary of State Hillary Clinton announced in late June that China and Singapore have met the requirements to get an exemption, bringing the number of exempted countries to 20. Countries that "significantly" cut back on the amount of crude oil imported from Iran are protected from U.S. sanctions.
The International Energy Agency states that Iranian crude oil imports have declined to the point that Tehran is out nearly $8 billion in oil revenue per quarter, Clinton said.
Edison had no public comment on the matter.